Find element by class name in Selenium Python - Build an Automation Script

Verify login button is clickable by class name

Preconditions (1)

Step 1: Locate the login button using its class name 'btn-login'

Step 2: Click the login button

Step 3: Verify that the page navigates to the dashboard URL 'https://example.com/dashboard'

✅ Expected Result: The login button is found by class name, clicked successfully, and the user is redirected to the dashboard page

Automation Requirements - Selenium with Python

Assertions Needed:

Assert the login button is present and clickable

Assert the current URL after clicking is 'https://example.com/dashboard'

Best Practices:

Use explicit waits to wait for the login button to be clickable

Use By.CLASS_NAME locator strategy

Handle exceptions if element is not found

Keep code readable and maintainable

Automated Solution

Selenium Python

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
from selenium.common.exceptions import TimeoutException

# Setup WebDriver (assuming chromedriver is in PATH)
driver = webdriver.Chrome()

try:
    # Open login page
    driver.get('https://example.com/login')

    # Wait up to 10 seconds for the login button to be clickable
    wait = WebDriverWait(driver, 10)
    login_button = wait.until(EC.element_to_be_clickable((By.CLASS_NAME, 'btn-login')))

    # Click the login button
    login_button.click()

    # Wait for URL to change to dashboard
    wait.until(EC.url_to_be('https://example.com/dashboard'))

    # Assert current URL is dashboard
    assert driver.current_url == 'https://example.com/dashboard', f"Expected dashboard URL but got {driver.current_url}"

    print('Test Passed: Login button clicked and dashboard loaded')

except TimeoutException:
    print('Test Failed: Element not found or page did not load in time')

finally:
    driver.quit()

This script uses Selenium WebDriver with Python to automate the manual test case.

First, it opens the login page URL.

Then it waits explicitly up to 10 seconds for the login button to be clickable using By.CLASS_NAME locator with the class name 'btn-login'. This ensures the element is ready before clicking.

After clicking the button, it waits until the URL changes to the expected dashboard URL.

Finally, it asserts the current URL matches the expected dashboard URL to confirm navigation succeeded.

TimeoutException is caught to handle cases where the element is not found or page load is slow.

The driver is closed in the finally block to clean up resources.

Common Mistakes - 4 Pitfalls

{'mistake': 'Using time.sleep() instead of explicit waits', 'why_bad': 'Hardcoded sleeps can make tests slow and flaky because they wait fixed time regardless of element readiness.', 'correct_approach': "Use Selenium's explicit waits like WebDriverWait with expected_conditions to wait only as long as needed."}

{'mistake': 'Using incorrect locator like By.ID when element only has class name', 'why_bad': "Locator won't find the element, causing NoSuchElementException.", 'correct_approach': 'Use By.CLASS_NAME with the exact class name to locate the element.'}

Not handling exceptions when element is not found

Clicking element before it is clickable

Bonus Challenge

Now add data-driven testing with 3 different class names for buttons on different pages

Show Hint

Practice

1. What does the Selenium method find_element(By.CLASS_NAME, "example") do?

easy

A. Finds elements by their ID "example".

B. Finds all elements with the class name "example" on the webpage.

C. Finds elements by their tag name "example".

D. Finds the first element with the class name "example" on the webpage.

Solution

1. Step 1: Understand the method purpose

   The method find_element locates a single element on the page.

2. Step 2: Identify the locator type

   Using By.CLASS_NAME means it looks for the first element with the given class name.

3. Final Answer:

   Finds the first element with the class name "example" on the webpage. -> Option D

4. Quick Check:

   find_element + CLASS_NAME = first matching element [OK]

Hint: find_element with CLASS_NAME finds only the first matching element [OK]

Common Mistakes:

• Confusing find_element with find_elements (plural)
• Using class name but expecting multiple elements
• Mixing class name with ID or tag name locators

2. Which of the following is the correct syntax to find an element by class name "btn-primary" using Selenium in Python?

easy

A. driver.find_element(By.CLASS_NAME, "btn-primary")

B. driver.find_element_by_class_name("btn-primary")

C. driver.find_element(By.CLASS, "btn-primary")

D. driver.find_element(By.CLASSNAME, "btn-primary")

Solution

1. Step 1: Recall the correct Selenium syntax

   In Selenium Python 4+, the recommended syntax is find_element(By.CLASS_NAME, "class").

2. Step 2: Check each option for correctness

   driver.find_element(By.CLASS_NAME, "btn-primary") uses the correct locator By.CLASS_NAME and method find_element. Others use deprecated or incorrect locators.

3. Final Answer:

   driver.find_element(By.CLASS_NAME, "btn-primary") -> Option A

4. Quick Check:

   Use By.CLASS_NAME with find_element [OK]

Hint: Use By.CLASS_NAME with find_element, not old deprecated methods [OK]

Common Mistakes:

• Using deprecated find_element_by_class_name method
• Wrong locator names like CLASS or CLASSNAME
• Missing quotes around class name string

3. Given the HTML snippet:

<div class="alert success">Success!</div>
<div class="alert error">Error!</div>

What text will this Selenium Python code print?

element = driver.find_element(By.CLASS_NAME, "alert")
print(element.text)

medium

A. "Success!"

B. "Error!"

C. "Success! Error!"

D. Throws NoSuchElementException

Solution

1. Step 1: Understand find_element behavior

   It finds the first element matching the class name "alert" in the HTML order.

2. Step 2: Identify the first matching element

   The first <div> with class "alert success" contains text "Success!".

3. Final Answer:

   "Success!" -> Option A

4. Quick Check:

   find_element returns first matching element's text [OK]

Hint: find_element returns first match only, so text is from first element [OK]

Common Mistakes:

• Assuming it returns all matching elements' text
• Confusing class names with multiple classes
• Expecting an error if multiple classes exist

4. What is wrong with this Selenium Python code snippet?

element = driver.find_element(By.CLASS_NAME, ".button")

medium

A. find_element should be find_elements to find class

B. Class name should not include the dot prefix "."

C. By.CLASS_NAME is not a valid locator

D. The class name must be uppercase

Solution

1. Step 1: Check the class name format

   When using By.CLASS_NAME, the class name should be given without any CSS selector symbols like ".".

2. Step 2: Identify the error in the code

   The code incorrectly includes a dot prefix ".button" which causes a failure to find the element.

3. Final Answer:

   Class name should not include the dot prefix "." -> Option B

4. Quick Check:

   Class name locator needs plain class name, no dot [OK]

Hint: Remove dot prefix when using By.CLASS_NAME locator [OK]

Common Mistakes:

• Adding dot prefix like CSS selectors to class name
• Using find_elements when only one element is needed
• Assuming class names must be uppercase

5. You want to click the first button with class "submit-btn" on a page. Which code snippet correctly finds and clicks it using Selenium Python?

hard

A. button = driver.find_elements(By.CLASS_NAME, "submit-btn")
button.click()

B. button = driver.find_element(By.ID, "submit-btn")
button.click()

C. button = driver.find_element(By.CLASS_NAME, "submit-btn")
button.click()

D. button = driver.find_element(By.CLASS_NAME, ".submit-btn")
button.click()

Solution

1. Step 1: Choose correct method to find single element by class

   Use find_element(By.CLASS_NAME, "submit-btn") to get the first matching element.

2. Step 2: Call click() on the found element

   After locating the element, call click() to perform the click action.

3. Final Answer:

   button = driver.find_element(By.CLASS_NAME, "submit-btn")\nbutton.click() -> Option C

4. Quick Check:

   find_element + CLASS_NAME + click() = correct usage [OK]

Hint: Use find_element with class name, then call click() on it [OK]

Common Mistakes:

• Using find_elements returns list, cannot call click() directly
• Using ID locator instead of class name
• Including dot prefix in class name