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Web Scraping with Selenium

Since the inception of the internet, no other automated data collection process supersedes web scraping. This is because there’s a large volume of data lying on the web that people can utilize for different purposes.

Web scraping, in its simplest form, is an automated process that uses a computer program to extract huge amounts of valuable data from web pages. But back in the days of encyclopedias, recipe books, and “blazing” internet speeds of 0.0024 Mbps, this process used to be complicated, time-consuming, and required expertise from data acquisition specialists. But thanks to the evolution of technology, you can now easily use online web scraper to conveniently scrape data from any website with just a few clicks or use Beautiful Soup. However, here we’ll focus on using Selenium to scrape data.

What is Selenium?

Selenium is an open-source automation tool created for automating web browsers to perform particular tasks. It provides tools that can interact with browsers to automate actions such as click, input, and select. Due to this ability, it makes for a perfect web scraping tool, especially when looking for useful data that may otherwise be inaccessible from other web scrapers. Here’s how to use Selenium for web scraping.

How to use Selenium for Web Scraping?

1. Set Up Selenium

To install Selenium, start by creating and activating a virtual environment to prevent clashes with other packages required for other projects. Then install the python binding for Selenium to allow for easy access to various Selenium web drivers such as chrome and firefox. You can now install Selenium by selecting a suitable and compatible driver for your browser version. Finally, unzip the file and move it to the virtual environment you’ve just created.

2. Install and Access WebDriver

A web driver enables you to open your browser and access your preferred website. This step may differ depending on the browser you’re using. Chrome works best with Selenium, though it also supports Firefox, Opera, Internet Explorer, and Safari. If you already have the Chrome web driver from the first step, create a driver variable using the direct path of the location of your downloaded web driver.

3. Access the Website

The next step is to access the website containing the data you need. Some web pages don’t allow data scraping as many data requests can cause server problems and also due to privacy and security concerns. However, most websites encourage data extraction so you won’t have a problem accessing the data. When you run the code for web scraping, a request is sent to the website’s URL. The server then responds by sending the website data and allowing you to access the HTML and XML page.

4. Locate the Data

  • To start extracting the information you want to scrape, you need to locate it first using an Xpath. This is a syntax that you can use for any element on a page on the internet.
  • To locate it, select the first item in the list of what you’re looking for.
  • Right-click
  • Then select the ‘inspect’ option to open up the developer tools.
  • In the developer tools, you’ll see the element you selected.
  • Easily translate it to its Xpath.
  • However, you need to consider the fact that you are not only looking for that one element but all related elements from the site.
  • Find the next element’s Xpath using the same process and identify the format that it uses. Then use that as the Selenium function to create the list of all the data you need from the site.

5. Apply the Function and Tie Everything Together

The advantage of using Selenium is that you’ll often be retrieving data located on multiple pages on the same website. For example, if you’re retrieving data from several years located on different pages, the difference may be the year at the end of the URL. Knowing this, you can create a function that loops through each year and accesses each URL individually using the same steps.

If you’d like to tie any additional information to the data you have collected, you can add it separately into a temporary data frame and then finally add it to a master data frame that carries all the data you’ve acquired in the desired format.

It is crucial to note that every website has its own reservations when it comes to data scraping. This means you cannot perform web scraping on all websites. Some even have legitimate restrictions in place which could lead to legal execution. However, some sites welcome and encourage web scrapers to access and retrieve data from their website, even providing an API to smoothen things for you. Either way, it’s better to check a site’s terms and conditions before attempting to scrape data.