Introduction to Selenium
Get started with Selenium, a powerful tool for browser automation and scraping JavaScript-rendered content.
Introduction to Selenium is a free Web Scraping & Bots lesson on CoddyKit — lesson 1 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Web Scraping & Bots learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Dynamic Content Challenge
Most websites today aren't static pages. They use JavaScript to load content after the initial page renders.
Think of social media feeds, search results that update as you scroll, or interactive forms. Traditional scraping tools (like Requests) often miss this content because they only fetch the initial HTML.
Meet Selenium WebDriver
Selenium WebDriver is a powerful tool designed to automate web browsers. Unlike libraries that just fetch HTML, Selenium actually launches a real browser (like Chrome or Firefox).
This means it can execute JavaScript, interact with elements, and see the web page exactly as a human user would, making it perfect for dynamic content.
Selenium's Core Idea
Selenium works by sending commands to a specific browser driver (e.g., ChromeDriver for Chrome, GeckoDriver for Firefox).
- Your Python script tells the driver what actions to perform.
- The driver then controls the actual browser.
- The browser executes these actions (navigating, clicking, typing) and returns the updated page state or data.
Install Selenium Library
First, let's install the Selenium library for Python. You can do this using pip, Python's package installer.
Open your terminal or command prompt and run:
pip install seleniumThis command downloads and installs the necessary Python components to interact with browsers.
Get Your Browser Driver
Selenium needs a specific browser driver to control your browser. For Chrome, you'll need ChromeDriver. For Firefox, it's GeckoDriver.
1. Check your browser version (e.g., Chrome -> Help -> About Google Chrome).
2. Download the matching driver from its official site:
- ChromeDriver: chromedriver.chromium.org
- GeckoDriver: github.com/mozilla/geckodriver
Place the downloaded driver executable (e.g., chromedriver.exe) in a location accessible by your system's PATH, or note its full path.
Launch Your First Browser
Let's write our first script to open a Chrome browser window using Selenium WebDriver.
Make sure your chromedriver is accessible (either in your PATH or specify its path directly in the Service object).
from selenium import webdriver
from selenium.webdriver.chrome.service import Service
import time
def main():
driver = None
try:
# IMPORTANT: Ensure ChromeDriver is installed and in your system PATH.
# If not, specify its path directly:
# service = Service("/path/to/your/chromedriver")
# driver = webdriver.Chrome(service=service)
driver = webdriver.Chrome() # Assumes chromedriver is in PATH
print("Chrome browser launched successfully!")
time.sleep(5) # Keep browser open for 5 seconds to observe
except Exception as e:
print(f"An error occurred: {e}")
finally:
if driver:
driver.quit() # Always close the browser
print("Browser closed.")
if __name__ == "__main__":
main()Go to a Web Page
Once the browser is open, you can tell it to navigate to any URL using the .get() method.
This is like typing a URL into the address bar and pressing Enter. The browser will load the page, including any JavaScript content.
from selenium import webdriver
import time
def main():
driver = None
try:
driver = webdriver.Chrome()
print("Browser launched.")
print("Navigating to example.com...")
driver.get("https://www.example.com")
print(f"Current page title: {driver.title}")
print(f"Current URL: {driver.current_url}")
time.sleep(5) # Keep browser open to see the page
except Exception as e:
print(f"An error occurred: {e}")
finally:
if driver:
driver.quit()
print("Browser closed.")
if __name__ == "__main__":
main()Waiting for Content
Web pages often take time to load completely, especially with dynamic content. Selenium provides ways to wait for elements to appear.
For now, we'll use a simple time.sleep() to pause execution. Later lessons will cover more robust explicit and implicit waits, which are more efficient.
time.sleep(seconds): Pauses execution for a fixed duration.
Always Close Your Browser
It's crucial to close the browser window when your script is done. This frees up system resources and prevents lingering browser processes.
Use the .quit() method on your WebDriver instance. This closes the browser and ends the WebDriver session cleanly.
from selenium import webdriver
import time
def main():
driver = None
try:
driver = webdriver.Chrome()
print("Browser launched.")
driver.get("https://www.example.com")
print(f"Navigated to: {driver.current_url}")
time.sleep(3) # Wait a bit to see the page
except Exception as e:
print(f"An error occurred: {e}")
finally:
if driver:
driver.quit() # This line closes the browser window
print("Browser closed successfully!")
if __name__ == "__main__":
main()Quick Check
You've launched your first browser with Selenium! What is the primary purpose of using Selenium WebDriver compared to libraries like Requests for web scraping?
Recap & Next Steps
In this lesson, you learned:
- Why Selenium is essential for handling dynamic web content.
- How to install the Selenium library and obtain a browser driver.
- To launch a browser, navigate to a URL, and close the session cleanly.
Next, we'll dive deeper into automating browser interactions like clicks, form submissions, and finding specific elements on a page!
Frequently asked questions
Is the “Introduction to Selenium” lesson free?
Yes — the full text of “Introduction to Selenium” is free to read here on the web, and the Web Scraping & Bots course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Web Scraping & Bots course, upgrade to CoddyKit PRO.
What will I learn in “Introduction to Selenium”?
Get started with Selenium, a powerful tool for browser automation and scraping JavaScript-rendered content. You practise Web Scraping & Bots with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Web Scraping & Bots?
No prior experience is required. Web Scraping & Bots on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Introduction to Selenium” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Web Scraping & Bots lesson?
Yes. Every Web Scraping & Bots lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.