Web scraping is the method of extracting data without interacting with an API or manually browsing the web. This is most often done by programming an automated tool to send requests to a web server, collect data (usually as HTML and other web page elements), and parse that data to extract the needed information.
This article is designed to serve not only as an introduction to web scraping but also as a comprehensive guide on how to use Selenium Python efficiently for web scraping.
Introduction to Web scraping
Initially, people used to collect information manually, which was a very slow and time-consuming process. People get engaged in the same tasks for many days. So, after this, the efficiency of data collection is increased. In some cases, it is easy to get structured data from websites, but if the data format/type is different, then it’s not as straightforward a process to extract data.
Web scraping is commonly used to extract information from different websites. It extracts data which has not been formatted, very poorly structured from the websites. Earlier web scraping was not able to directly put data into an Excel which could lead to manual errors.
These manual errors have now been minimized or, rather, eliminated since web scraping has become more functional and accurate at storing data in different structures and formats; this allows further operations based on the provided structured data.
In this process, many Python libraries are also directly involved so that data can be structured using simplified code. Some basic knowledge of HTML, DOM, and other programming languages is a must to write software for data extraction or crawling.
Applications of Web Scraping
Web Scraping comes with a handful of applications that help the user. Following are the applications of Web Scraping:
- Sentiment Analysis :
Although many websites utilized for analyzing sentiment, like social media sites, provide APIs for data access, this may not always be sufficient. Gathering data through web scraping is frequently better to access up-to-the-minute details, discussions, studies, and patterns.
- Machine Learning :
Although sentiment analysis is a widely used machine learning algorithm, it is just one of several available options. All machine learning algorithms share the need for a substantial amount of data to be trained effectively. Machine learning is driving research, technological advancement, and overall growth in all areas of learning and innovation. Web scraping, in return, can provide high-precision and dependable data gathering for these algorithms.
- Market Research :
eCommerce vendors can monitor products and pricing on various platforms to analyze consumer attitudes and competitor pricing. This enables effective tracking of rivals and price comparisons, ensuring a thorough market understanding.
- Technological Research :
Data is needed for driverless cars, face recognition, and recommendation engines. Web scraping is a popular method for efficiently collecting information and is commonly used to extract useful data from trustworthy websites.
What is Selenium?
Selenium is an open source framework for automating web browsers. It is used for testing web applications, performing automation tasks and scraping data from websites. It supports multiple programming languages including Python, c-sharp, Java and Ruby.
The Several components of Selenium are:
- Selenium Integrated Development Environment (IDE) :
Serves as a toolkit for web testing and allows users to capture and replay interactions with web applications.
- Selenium RC (Remote Control) :
It allowed testers to write automated tests for web applications in many programming languages like C#, Python, Java etc.
- Selenium WebDriver :
It offers a programming interface to interact with web browsers and also provides a rich set of APIs.
- Selenium Grid:
It is a server that executes tests in web browsers across various platforms or operating systems.
Selenium for Web Scraping
Web scraping involves two broad categories of web pages – pages that need rendering and pages that do not need rendering. Web scraping the pages that need rendering is often called web scraping dynamic web pages. This is where Selenium comes into play.
Selenium is one of the oldest and perhaps the most widely known tool. Selenium development began as early as 2004. This began as a tool for functional testing and the potential of web scraping was soon realized.
The biggest reason for Selenium is that it supports writing scripts in multiple programming languages, including Python. It means that you can write Python code to mimic human behavior. The Python script will open the browser, visit web pages, enter text, click buttons, and copy text. This can be combined with other features in Python to save data in simple CSV or complex databases.
Advantages of using Selenium and Python for Web Scraping
The use of Python and Selenium for web scraping gives numerous benefits when compared to other web scraping methods:
- Dynamic Websites :
JavaScript or other scripting languages are used to create dynamic web pages. These pages frequently have visible elements that appear either after the page finishes loading or upon user interaction. Selenium has the ability to engage with these components, which enhances its effectiveness in gathering information from dynamic web pages.
- User Interactions :
Selenium is capable of mimicking user actions such as clicking, submitting forms, and scrolling. This enables you to extract information from websites that demand user interaction, like logging in.
- Debugging :
Selenium has the capability to operate in debug mode. This enables the users to navigate through the scraping process and observe the actions of the scraper at each stage. This is beneficial for identifying and resolving issues when troubleshooting problems.
Setting Up Selenium and Python for Web Scraping
In this article, we will use Python 3. The code should work with any version of Python above 3.6.
Setting up Selenium involves setting up two components—the Selenium package for Python and the driver for the browser that you want to use.
Selenium Package:
Firstly, to download the Selenium package, execute the pip command in your terminal:
Instructions for Windows users
- Download the Python 3 installer from the official Python website. Run the installer and proceed with the on-screen instructions to finish the installation.
- Start a command prompt via the cmd.exe program, and then run the pip command listed below to install Selenium.
You can now execute your test scripts using Python. For example, if you have created a Selenium-based script and saved it inside
,
You can run it like this:
Selenium Drivers
Depending on your operating system and your preferred browser, the source of downloads would differ. In this example, we are going to work with Chrome. Verify the version of Chrome installed by clicking the 3 dots on the top right of the Chrome, then point to About and select About Chrome. Take note of the version number. You will need to know your version to get the appropriate driver.
You can find the links to download the drivers for Firefox, Chrome, and Edge here.
Once you download the executable appropriate for your operating system, extract it and place it in a folder. The next step would be to take note of the folder path. You can append this path to your PATH environment variable, or, optionally, this folder path can also be provided in the code.
This will launch Chrome and load the web page. There will be notice below the address bar:
To close this browser, simply run this line:
Data Extraction with Selenium – Locating Elements
The first step of extracting the data is to locate the elements. Selenium offers a variety of find element methods to help locate elements on a page:
- find_element_by_id
- find_element_by_name
- find_element_by_xpath
- find_element_by_css_selector
- find_element_by_link_text
- find_element_by_partial_link_text
- find_element_by_tag_name
- find_element_by_class_name
All these methods return one instance of WebElement.
As an example, let’s try and locate the H1 tag on xyz.com homepage with Selenium:
You can also use the find_elements (plural form) to return a list of elements. E.g.:-
This way, you’ll get all anchors on the page.
However, these will be cases when you need to define more complex selectors. This can be achieved using CSS selectors or XPath Selectors.
Static and Dynamic Selenium and Python Web Scraping
The following explains static and dynamic selenium and Python web scraping.
Static Web Scraping
Static web scraping involves retrieving data from unchanging HTML content on web pages. Python and Selenium have the capability to automate the process of navigating through static websites, identifying particular sections, and retrieving information. This technique is ideal for reliable website layouts, removing the necessity for intricate interactions or JavaScript rendering.
Dynamic Web Scraping
Dynamic web scraping is crucial for websites that utilize JavaScript or AJAX to load dynamic content. Python, along with Selenium, can replicate actions performed by users such as clicking buttons, submitting forms, and scrolling. This allows for the data to be fetched only after the execution of JavaScript or AJAX requests, introducing new scraping opportunities.
General Method to be Followed When Performing Web Scraping
Below is an outline of the typical procedure used for conducting web scraping :
- Identifying Target Website: Identify the specific website from which you wish to retrieve information. Make sure you have authorization to collect data from the website and check all applicable terms of service or legal issues.
- Choosing the right tools: Choose the right web scraping tools according to your scraping project’s specific needs. Popular libraries in Python, like Beautiful Soup, Scrapy, and Selenium, offer various capabilities and functionalities for users.
- Inspecting Website’s Structure: Utilize the developer tools in your web browser to examine the HTML layout of the desired website. Recognize the components that hold the data you need to retrieve, like tags, classes, or IDs.
- Developing the Scraping code: Develop your code for web scraping using the selected tools and programming language. Use methods such as analyzing HTML, filling out forms, selecting buttons, or exploring different pages to obtain the necessary information.
- Handling captchas and authentication: Certain websites might use security measures like captchas or user authentication to deter scraping. Introduce strategies to tackle these obstacles, like utilizing captcha-solving services or sharing login information.
- Implementing Data Extraction: Use the specified HTML tags and CSS attributes to retrieve the necessary information from the webpage. Then, use parsing techniques, regular expressions, or dedicated library functions to extract and structure the data in a practical format.
- Handling Pagination and Iteration: To deal with pagination on a website with multiple pages or steps, use methods like cycling through URLs or selecting the “Next” buttons when necessary.
- Storing and Analyzing the Extracted Data: Store the extracted data in an organized form, like CSV, JSON, or a database. Conduct all required data cleaning, transformation, or analysis to uncover insights or incorporate them into your application or system.
Leverage tools like LambdaTest for testing and validating your scraping scripts across various browsers. LambdaTest is an AI-powered test orchestration and execution platform that lets you perform manual and automation testing at scale with over 3000+ real devices, browsers, and OS combinations.
Conclusion
In this article, we have learned how to utilize the Python Selenium web scraping technique to extract data from a website. We have grasped the various scraping methods and situations. We saw the necessity of verifying the legality of scraping. We have also discussed the increasing value of data in various fields and applications worldwide. I trust this article has given you all the information you need regarding Web Scraping with Selenium and Python.