Scraping JavaScript-Intensive Websites Like an Expert Using Python

Best Tool for this Job

Normally, we would suggest some go-to libraries to do web scraping:

BeautifulSoup

Requests

While the previously mentioned tools can handle various tasks, they cannot render JavaScript. Fortunately, there is a dedicated category of tools designed specifically for this purpose called Browser Automation tools.

Browser Automation tools are built to simulate and automate the web browsing experience, allowing tasks to be executed at intervals or speeds surpassing human capabilities. While these tools are commonly used for website testing by owners, they also offer the functionality required to render JavaScript and scrape the underlying data.

These tools provide:

A comprehensive solution.

Combining JavaScript rendering capabilities with web scraping functionality.

Making them ideal for extracting data from JavaScript-intensive websites.

By leveraging Browser Automation tools, you can effectively overcome the challenge of scraping websites that rely heavily on JavaScript.

Among the popular tools are:

• Scrapy
• Playwright
• Selenium

For the purpose of this example, let's delve into using Selenium. Additionally, we will utilize the reliable BeautifulSoup library to parse the response and extract the desired data.

Set up a Workspace

To fully automate a web browser, some additional setup is necessary beyond the basic installation of libraries. We will need to install the following components:

Chrome Browser (or any other web browser of your choice, but we will use Chrome for this example).

ChromeDriver: This is the web driver specific to Chrome that allows interaction with the browser programmatically.

To follow along, you can install Chrome on your system. As for ChromeDriver installation, we can use a convenient Python library that handles the installation for us.

With that in mind, let's proceed with installing the required libraries.

Once they get installed, we could start importing:

To simplify the installation process, we can use the chromedriver_autoinstaller library, which automatically installs ChromeDriver and adds it to the system's PATH if it's not already present. This saves us some effort and can be achieved with a single line of code:

By executing this code, the library will handle the installation of ChromeDriver seamlessly.

Here's a summary of the steps we've taken to set up our environment. Assuming you have already installed Python, you can use pip to install the necessary libraries. After installing selenium, bs4, and chromedriver-autoinstaller, your Python file should look something like this:

Get a Webpage

Now that we have our environment set up, we can start making web page requests. To accomplish this, we need to configure the WebDriver object that Selenium will use. Here's an example of how you can set it up:

Now we can instruct the webdriver to retrieve a web page. For this example, we'll scrape Rotten Tomatoes Certified Fresh Movies.

Although the data we want (movie titles, ratings, etc.) can be obtained without rendering JavaScript, it's much easier to parse when it's rendered.

This page heavily relies on JavaScript, as shown in the JavaScript-enabled site:

And using JavaScript disabled:

We can ask for this web page using driver object “get” method

And we could get an html output with a page_source attribute:

Just to do recap, let’s go through the code:

Parse the HTML

Now, Selenium can handle parsing the data, but in most cases, we'll rely on BeautifulSoup for parsing the HTML. Let's create a BeautifulSoup object from the page source:

Now, we need to have something which will look like this:

If we were to print the soup object we've created, we would see the entire web page, excluding some of the fancy formatting. Fortunately, in this case, we don't have to wait for JavaScript execution.

However, in some scenarios, we may need to wait for JavaScript execution. This can be achieved either through Implicit Waiting or Explicit Waiting.

Since we don't need to worry about that here, let's focus on finding the information we're interested in:

It appears that all the movies we're interested in are contained within div elements with the class "mb-movie". Each of these divs contains information about an individual movie.

To extract the relevant information, we can use BeautifulSoup's find_all() method with the appropriate parameters:

We can have each of them and find a title, release date, and score and easily using BeautifulSoup:

Conclusion

In summary, we have accomplished several tasks in a short period of time:

Installed Chrome and ChromeDriver.

Used a Python library to install ChromeDriver automatically.

Fetched a web page that heavily relies on JavaScript using Selenium.

Parsed and extracted data from the web page using BeautifulSoup.

Here's a final overview of our progress, with the data printed in the terminal:

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