Selenium Python Tutorial (with Example)
By Shaumik Daityari, Community Contributor - September 3, 2024
New features are regularly added to web applications to boost user engagement. To ensure these updates work as intended and that the user interface remains functional, automated testing is crucial. Selenium is a widely-used tool for this type of automation testing.
Selenium is an open-source automation testing tool that supports various scripting languages such as C#, Java, Perl, Ruby, JavaScript, and others. The choice of scripting language can be made based on the specific requirements of the application being tested.
Python is one of the most popular choices when it comes to scripting with 51% of the developers using it, as suggested by the StackOverflow 2024 annual survey.
- Why do Developers prefer Python for writing Selenium Test Scripts?
- Getting Started with Selenium Python
- Selenium Python Example: How to run your first Test?
- Interacting with Common Elements in Selenium
- Navigate through HTML DOM Elements
- Step 1. Locate and Interact with Navigation Links
- Step 2. Access and Interact with Header Sections
- Step 3. Interact with Forms and Input Fields
Why do Developers prefer Python for writing Selenium Test Scripts?
Developers prefer Python for writing Selenium test scripts because of its simplicity, readability, and ease of use. Python’s clear and concise syntax allows for faster script development and easier maintenance, which is crucial in testing scenarios.
Additionally, Python has a rich set of libraries and frameworks that complement Selenium, making it easier to handle complex tasks such as data manipulation, reporting, and integration with other tools.
Python’s extensive community support and documentation also provide valuable resources for troubleshooting and improving test scripts. These factors make Python a popular choice for Selenium automation.
Getting Started with Selenium Python
Getting started with Selenium using Python involves setting up an environment where you can write and run automated test scripts for web applications.
Selenium, combined with Python, offers a powerful and easy-to-learn toolset for automating browser interactions. Python’s simple syntax makes it ideal for quickly writing clear and maintainable test scripts.
To begin, you’ll need to install the Selenium WebDriver, set up a compatible browser, and learn the basics of locating web elements, interacting with them, and running test cases. This combination is perfect for testing dynamic and responsive web applications efficiently.
Selenium Python Example: How to run your first Test?
To run Selenium Python Tests here are the steps to follow:
Step 1. Import the Necessary Classes
First, you’ll need to import the WebDriver and Keys classes from Selenium. These classes help you interact with a web browser and emulate keyboard actions.
from selenium import webdriver from selenium.webdriver.common.keys import Keys
- webdriver: Allows you to control the browser.
- Keys: Lets you simulate keyboard key presses.
Step 2. Create a WebDriver Instance
To interact with a browser, you’ll need to create an instance of WebDriver. In this example, we use Chrome:
driver = webdriver.Chrome('./chromedriver')
Make sure chromedriver is in the same directory as your Python script. This command opens a new Chrome browser window.
Step 3. Load a Website
Use the .get() method to navigate to a website. This method waits for the page to load completely:
driver.get("https://www.python.org")
This will open Python’s official website in the browser.
Step 4. Check the Page Title
Once the page is loaded, you can retrieve and print the page title to verify you’re on the right page:
print(driver.title)
You should see:
Welcome to Python.org
Step 5. Interact with the Search Bar
To perform a search, locate the search bar element, enter a query, and submit it. Here’s how to find the search bar by its name attribute and interact with it:
search_bar = driver.find_element_by_name("q") search_bar.clear() search_bar.send_keys("getting started with python") search_bar.send_keys(Keys.RETURN)
As an explanation :
- find_element_by_name(“q”): Finds the search bar element.
- clear(): Clears any existing text.
- send_keys(“getting started with python”): Types the query into the search bar.
- send_keys(Keys.RETURN): Simulates pressing the Return (Enter) key.
Step 6. Verify the Resulting URL
After submitting the search query, you can check the updated URL to confirm the search results page:
print(driver.current_url)
You should see a URL similar to:
https://www.python.org/search/?q=getting+started+with+python&submit=
Step 7. Close the Browser
Finally, close the browser session to end the test:
driver.close()
Summary :
Here is the complete script for your first Selenium test in Python. Save this code in a file named selenium_test.py and run it using python selenium_test.py:
from selenium import webdriver from selenium.webdriver.common.keys import Keys # Create a new instance of the Chrome driver driver = webdriver.Chrome('./chromedriver') # Open the Python website driver.get("https://www.python.org") # Print the page title print(driver.title) # Find the search bar using its name attribute search_bar = driver.find_element_by_name("q") search_bar.clear() search_bar.send_keys("getting started with python") search_bar.send_keys(Keys.RETURN) # Print the current URL print(driver.current_url) # Close the browser window driver.close()
Interacting with Common Elements in Selenium
Selenium allows you to perform a variety of actions on web elements. You have already touched upon entering input, here’s how to interact with buttons, and dropdowns:
Assuming you want to click a button with the ID “submit-button” after entering the input in the search bar :
# Locate the button by its ID attribute button = driver.find_element_by_id("submit-button") # Click the button button.click()
If you need to click a link by its text:
# Locate the link by its link text link = driver.find_element_by_link_text("Click Here") # Click the link link.click()
Explanation:
- find_element_by_id(“submit-button”): Finds the button with the ID “submit-button”.
- find_element_by_link_text(“Click Here”): Finds a link with the text “Click Here”.
- click(): Simulates a mouse click on the element.
Though dropdowns are not present on this site, they are quite common for web application testing
For dropdown menus, Selenium provides the Select class to handle options within <select> elements.
Example: Selecting an Option from a Dropdown
Assuming you have a dropdown menu with the ID “dropdown-menu”:
from selenium.webdriver.support.ui import Select # Locate the dropdown menu by its ID attribute dropdown = Select(driver.find_element_by_id("dropdown-menu")) # Select an option by visible text dropdown.select_by_visible_text("Option 1") # Or select an option by value dropdown.select_by_value("option1") # Or select an option by index (0-based index) dropdown.select_by_index(0)
Explanation:
- Select(driver.find_element_by_id(“dropdown-menu”)): Creates a Select object for the dropdown menu.
- select_by_visible_text(“Option 1”): Selects an option by its visible text.
- select_by_value(“option1”): Selects an option by its value attribute.
- select_by_index(0): Selects an option by its index in the dropdown.
Navigate through HTML DOM Elements
The HTML Document Object Model (DOM) represents the structure of a web page as a tree of objects. Selenium allows you to interact with these elements using various locator strategies.
In our first test script, we have already used some of the methods used to navigate DOM elements. This section will be a slightly more detailed view into how you can use different methods to locate and interact with elements on the Python.org website.
Step 1. Locate and Interact with Navigation Links
Example: Clicking the “Downloads” Link
To click the “Downloads” link, you can use the .find_element_by_link_text() method, but here’s how to use other locators to achieve the same, example by using find_element_by_xpath:
from selenium import webdriver # Set up the WebDriver driver = webdriver.Chrome('./chromedriver') # Open the Python website driver.get("https://www.python.org/") # Locate the "Downloads" link using XPath downloads_link = driver.find_element_by_xpath("//a[text()='Downloads']") # Click the "Downloads" link downloads_link.click() # Optionally, print the current URL to confirm navigation print(driver.current_url) # Close the browser driver.close()
Explanation:
XPath: //a[text()='Downloads']
locates the “Downloads” link based on its visible text.
Step 2. Access and Interact with Header Sections
Example: Accessing the Main Header
To access the main header text, you can use different locators to find the header element.
Using find_element_by_class_name:
from selenium import webdriver # Set up the WebDriver driver = webdriver.Chrome('./chromedriver') # Open the Python website driver.get("https://www.python.org/") # Locate the header element using its class name header = driver.find_element_by_class_name("introduction") # Print the text of the header print(header.text) # Close the browser driver.close()
Explanation:
- Class Name: “introduction” is used to find the header element based on its class.
Step 3. Interact with Forms and Input Fields
Example: Filling Out and Submitting the Search Form
To interact with the search form, you can use the .find_element_by_name() method to locate the input field.
Using find_element_by_name:
from selenium import webdriver from selenium.webdriver.common.keys import Keys # Set up the WebDriver driver = webdriver.Chrome('./chromedriver') # Open the Python website driver.get("https://www.python.org/") # Locate the search bar using its name attribute search_bar = driver.find_element_by_name("q") # Clear any existing text and enter a new search term search_bar.clear() search_bar.send_keys("Python Documentation") search_bar.send_keys(Keys.RETURN) # Optionally, print the current URL to confirm search results print(driver.current_url) # Close the browser driver.close()
Explanation:
- Name Attribute: find_element_by_name(“q”) locates the search input field by its name attribute.
Navigate through Windows and Frames
When working with multiple browser windows or tabs, or dealing with iframes (frames), you may need to switch contexts to interact with different elements.
Step 1. Handling Multiple Browser Windows or Tabs
Example: Switching Between Windows
To handle multiple browser windows or tabs:
from selenium import webdriver from selenium.webdriver.common.keys import Keys import time # Set up the WebDriver driver = webdriver.Chrome('./chromedriver') # Open the Python website driver.get("https://www.python.org/") # Open a new tab with a different URL driver.execute_script("window.open('https://www.google.com', '_blank');") # Switch to the new tab driver.switch_to.window(driver.window_handles[1]) # Perform actions in the new tab (e.g., search for 'Selenium') search_bar = driver.find_element_by_name("q") search_bar.clear() search_bar.send_keys("Selenium") search_bar.send_keys(Keys.RETURN) # Switch back to the original tab driver.switch_to.window(driver.window_handles[0]) # Close the browser driver.quit()
Explanation:
- window_handles: Retrieves a list of window handles. Switch to a specific window using switch_to.window().
- execute_script(“window.open()”): Opens a new tab or window.
Step 2. Switching Between Frames
Example: Switching to an iFrame
To switch to and interact with elements within an iframe:
from selenium import webdriver from selenium.webdriver.common.keys import Keys import time # Set up the WebDriver driver = webdriver.Chrome('./chromedriver') # Open the Python website driver.get("https://www.python.org/") # Example site with iframe (replace with an actual URL that contains iframes) driver.get("https://www.w3schools.com/html/html_iframe.asp") # Switch to the iframe using its name or ID driver.switch_to.frame("iframeResult") # Perform actions within the iframe print(driver.find_element_by_tag_name("h1").text) # Switch back to the default content driver.switch_to.default_content() # Close the browser driver.quit()
Explanation:
- switch_to.frame(): Switches to a specific iframe.
- switch_to.default_content(): Switches back to the main page.
Handling Waits
Dynamic content can load at different times, so using waits helps ensure elements are present before interacting with them.
Step 1. Implicit Waits
Example: Using Implicit Waits
from selenium import webdriver # Set up the WebDriver driver = webdriver.Chrome('./chromedriver') # Set implicit wait driver.implicitly_wait(10) # seconds # Open the Python website driver.get("https://www.python.org/") # Locate an element with implicit wait search_bar = driver.find_element_by_name("q") search_bar.send_keys("Python") # Close the browser driver.quit()
Explanation:
- implicitly_wait(): Sets a default wait time for finding elements. If an element is not immediately found, WebDriver will wait up to the specified time.
Step 2. Explicit Waits
from selenium import webdriver from selenium.webdriver.common.by import By from selenium.webdriver.support.ui import WebDriverWait from selenium.webdriver.support import expected_conditions as EC # Set up the WebDriver driver = webdriver.Chrome('./chromedriver') # Open the Python website driver.get("https://www.python.org/") # Define WebDriverWait with a maximum wait time of 10 seconds wait = WebDriverWait(driver, 10) # Wait for the search bar to be present in the DOM search_bar = wait.until(EC.presence_of_element_located((By.NAME, "q"))) # Perform actions on the search bar search_bar.send_keys("Python") # Close the browser driver.quit()
Explanation:
- WebDriverWait(driver, 10): Creates an instance of WebDriverWait, specifying a maximum wait time of 10 seconds.
- wait.until(EC.presence_of_element_located((By.NAME, “q”))): Pauses the script until the search bar element is found by its name attribute. If the element is not found within 10 seconds, a TimeoutException will be raised.
Assertions and Validations
To ensure that the application behaves as expected, you can use assertions and validations.
Verifying Expected Conditions Using Assertions
Example: Verifying Page Title and Search Results
from selenium import webdriver from selenium.webdriver.common.keys import Keys from selenium.webdriver.support.ui import WebDriverWait from selenium.webdriver.support import expected_conditions as EC # Set up the WebDriver driver = webdriver.Chrome('./chromedriver') # Open the Python website driver.get("https://www.python.org/") # Use WebDriverWait to wait for the search bar to be present wait = WebDriverWait(driver, 10) search_bar = wait.until(EC.presence_of_element_located((By.NAME, "q"))) # Perform search search_bar.send_keys("Python") search_bar.send_keys(Keys.RETURN) # Verify the title contains "Python" assert "Python" in driver.title # Verify search results contain expected text results = wait.until(EC.presence_of_element_located((By.CSS_SELECTOR, "ul.list-recent-events"))) assert "Python" in results.text # Print the results to verify print(driver.title) print(results.text) # Close the browser driver.quit()
Explanation:
- Assertions: Used to check if the conditions are met. For example, checking if the title or text of elements matches expected values.
- assert: Verifies conditions and will raise an AssertionError if the condition is not true.
Handling Alerts and Pop-ups
Web applications often use JavaScript alerts, confirmation dialogs, or prompts to interact with users. Selenium provides ways to handle these pop-ups effectively.
Dealing with JavaScript Alerts
JavaScript alerts are simple pop-up messages that require user interaction to dismiss. Selenium allows you to interact with these alerts using the switch_to.alert() method.
from selenium import webdriver from selenium.webdriver.common.by import By from selenium.webdriver.common.keys import Keys # Set up the WebDriver driver = webdriver.Chrome('./chromedriver') # Open a website that triggers an alert (example URL) driver.get("https://www.selenium.dev/selenium/docs/api/java/org/openqa/selenium/Alert.html") # Click a button that triggers an alert trigger_alert_button = driver.find_element(By.ID, "alertButton") # Adjust locator as needed trigger_alert_button.click() # Switch to the alert and accept it alert = driver.switch_to.alert print("Alert text:", alert.text) alert.accept() # Close the browser driver.quit()
Explanation:
- switch_to.alert: Switches the context to the alert. Once switched, you can interact with the alert.
- alert.accept(): Accepts the alert, which is equivalent to clicking “OK” on the alert.
Other Alert Actions:
- alert.dismiss(): Clicks “Cancel” on a confirmation dialog.
- alert.send_keys(“text”): Sends text to a prompt dialog (if applicable).
Cleanup and Teardown
Properly closing the browser session is crucial for releasing resources and ensuring that your automation script runs cleanly.
Properly Closing the Browser Session
Example: Closing the Browser
from selenium import webdriver # Set up the WebDriver driver = webdriver.Chrome('./chromedriver') # Open a website driver.get("https://www.python.org/") # Perform actions (e.g., search) search_bar = driver.find_element(By.NAME, "q") search_bar.send_keys("Python") search_bar.send_keys(Keys.RETURN) # Cleanup: Close the browser driver.quit()
Explanation:
- driver.quit(): Closes all browser windows and ends the WebDriver session. This is the preferred method for cleanup as it ensures the browser process is terminated and resources are freed.
Alternative Methods:
- driver.close(): Closes the current window. If it’s the only window open, it will end the session. Use driver.quit() for complete cleanup.
Testing Framework Integration
Integrating Selenium tests with a testing framework provides structured test cases, reporting, and additional functionality such as setup and teardown methods.
1. Integrate with unittest Framework
unittest is a built-in Python testing framework that provides a structured approach to writing and running tests, including test case management, fixtures, and test discovery. Integrating Selenium with unittest allows for organized test cases, setup and teardown methods, and detailed test reports, making it easier to manage and maintain automated tests.
Example: Basic Test with unittest
import unittest from selenium import webdriver from selenium.webdriver.common.by import By from selenium.webdriver.common.keys import Keys class PythonOrgSearchTest(unittest.TestCase): @classmethod def setUpClass(cls): cls.driver = webdriver.Chrome('./chromedriver') cls.driver.get("https://www.python.org/") def test_search_python(self): search_bar = self.driver.find_element(By.NAME, "q") search_bar.send_keys("Python") search_bar.send_keys(Keys.RETURN) self.assertIn("Python", self.driver.title) @classmethod def tearDownClass(cls): cls.driver.quit() if __name__ == "__main__": unittest.main()
Explanation:
- unittest.TestCase: Defines a test case class. Each method within the class represents a test case.
- setUpClass(): Initializes resources needed for the tests. Runs once before any test methods are executed.
- tearDownClass(): Cleans up resources. Runs once after all test methods have completed.
- unittest.main(): Runs the tests and provides output in the console.
Read More: Top 8 Python Testing Frameworks in 2024
2. Integrate with pytest Framework
pytest is a powerful and flexible Python testing framework that simplifies writing tests with its rich feature set, including fixtures, parameterized tests, and detailed assertions. Integrating Selenium with pytest enhances test organization, facilitates advanced setup/teardown functionality, and generates comprehensive test reports, improving test reliability and clarity.
Example: Basic Test with pytest
import pytest
from selenium import webdriver from selenium.webdriver.common.by import By from selenium.webdriver.common.keys import Keys @pytest.fixture(scope="module") def driver(): driver = webdriver.Chrome('./chromedriver') yield driver driver.quit() def test_search_python(driver): driver.get("https://www.python.org/") search_bar = driver.find_element(By.NAME, "q") search_bar.send_keys("Python") search_bar.send_keys(Keys.RETURN) assert "Python" in driver.title
Explanation:
- pytest.fixture(): Defines a fixture that sets up and tears down resources. The scope=”module” ensures the fixture is run once per module.
- yield: Provides the driver instance to the test function and performs cleanup after the test completes.
- assert: Checks that the condition is met. pytest will report the assertion failure if the
Run Selenium Python Tests on Real Devices
Selenium Python Resources
- Selenium Python Tutorial (with Example)
- Page Object Model and Page Factory in Selenium Python
- Understanding ExpectedConditions in Selenium
- Understanding Role of Thread.sleep() in Selenium
- Headless Browser Testing With Selenium Python
- How to install GeckoDriver for Selenium Python?
- How to perform Web Scraping using Selenium and Python
- How to Create and Use Action Class in Selenium Python
- How to download a file using Selenium and Python
- How to Press Enter without Element in Selenium Python?
- UI Automation using Python and Selenium: Tutorial
- Get Current URL in Selenium using Python: Tutorial
Best Practices using Selenium WebDriver with Python
Here are five best practices for using Selenium WebDriver with Python:
- Use Explicit Waits: Prefer explicit waits over implicit waits to handle dynamic content. Explicit waits ensure that your script interacts with elements only when they are ready, reducing the chances of encountering timing issues.
- Organize Tests with Frameworks: Integrate Selenium tests with testing frameworks like unittest or pytest to structure your test cases, manage setup and teardown, and generate detailed test reports.
- Use Page Object Model (POM): Implement the Page Object Model to separate test logic from page-specific code. This design pattern promotes code reusability, maintainability, and easier updates.
- Handle Exceptions Carefully: Implement error handling and logging to manage unexpected situations, such as element not found or timeout errors. This helps in debugging and provides insights into test failures.
- Optimize Browser Performance: Run tests in headless mode or use browser profiles to speed up test execution and reduce resource consumption. Also, ensure that browser drivers are up-to-date for compatibility and performance improvements.
Why run Selenium Python Tests on BrowserStack Real Device Cloud?
Running Selenium Python tests on BrowserStack’s Real Device Cloud offers numerous advantages that significantly enhance testing efficiency and effectiveness.
BrowserStack provides access to a wide range of real devices and browsers, ensuring that tests reflect real-world scenarios and uncover device-specific issues. The platform supports scalable parallel execution, allowing multiple tests to run simultaneously across various configurations, which accelerates the development cycle.
Cross-platform testing on BrowserStack ensures consistent application performance across different environments. Additionally, it offers real-time debugging features such as live logs, screenshots, and video recordings, which aid in quick troubleshooting.
Seamless integration with CI/CD pipelines further automates the testing process, enabling tests to run on every code change and providing immediate feedback on application quality. Overall, BrowserStack Automate enables comprehensive, efficient, and reliable testing, fostering continuous development and deployment.