Find element by ID in Selenium Python - Build an Automation Script

Verify login button is clickable by finding element using ID

Preconditions (1)

Step 1: Locate the login button using its ID 'loginBtn'

Step 2: Click the login button

✅ Expected Result: The login button is found by ID and clicked successfully without errors

Automation Requirements - selenium

Assertions Needed:

Assert that the login button element is present before clicking

Assert that after clicking, the current URL changes to the dashboard page URL 'https://example.com/dashboard'

Best Practices:

Use explicit waits to wait for the element to be present and clickable

Use By.ID locator strategy for finding the element

Use try-except blocks to handle exceptions gracefully

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

# Initialize the Chrome driver
with webdriver.Chrome() as driver:
    driver.get('https://example.com/login')

    wait = WebDriverWait(driver, 10)

    # Wait until the login button is present and clickable
    login_button = wait.until(EC.element_to_be_clickable((By.ID, 'loginBtn')))

    # Assert the login button is displayed
    assert login_button.is_displayed(), 'Login button is not visible'

    # Click the login button
    login_button.click()

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

    # Assert the URL is correct
    assert driver.current_url == 'https://example.com/dashboard', 'Did not navigate to dashboard after login'

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

First, it opens the login page URL.

Then it uses an explicit wait to find the login button by its ID 'loginBtn' and waits until it is clickable.

It asserts the button is visible before clicking it.

After clicking, it waits for the URL to change to the dashboard URL and asserts the navigation succeeded.

Using explicit waits ensures the test does not fail due to timing issues.

Using By.ID locator is the most direct and reliable way to find the element by its unique ID.

Common Mistakes - 3 Pitfalls

Using time.sleep() instead of explicit waits

{'mistake': 'Using find_element_by_id() which is deprecated', 'why_bad': 'Deprecated methods may be removed in future Selenium versions and cause code breakage.', 'correct_approach': "Use driver.find_element(By.ID, 'id_value') as per the latest Selenium API."}

Not checking if the element is visible before clicking

Bonus Challenge

Now add data-driven testing with 3 different login button IDs to verify each is clickable

Show Hint

Practice

1. What is the correct way to find an element by its ID using Selenium in Python?

easy

A. driver.find_element(By.CLASS_NAME, "element_id")

B. driver.find_element(By.ID, "element_id")

C. driver.find_element_by_id("element_id")

D. driver.find_element(By.NAME, "element_id")

Solution

1. Step 1: Understand Selenium's recommended syntax

   In Selenium Python, the preferred way to find elements by ID is using find_element(By.ID, "id") with the By class.

2. Step 2: Compare options

   driver.find_element(By.ID, "element_id") uses the correct syntax. driver.find_element_by_id("element_id") is deprecated in newer Selenium versions. Options A and D use wrong locator strategies.

3. Final Answer:

   driver.find_element(By.ID, "element_id") -> Option B

4. Quick Check:

   Use By.ID for ID locator [OK]

Hint: Always use By.ID with find_element for IDs [OK]

Common Mistakes:

• Using deprecated find_element_by_id method
• Confusing ID with class or name locators
• Missing import of By class

2. Which of the following is the correct import statement to use By.ID in Selenium Python?

easy

A. from selenium.webdriver.common.by import By

B. import selenium.webdriver.By as By

C. from selenium.webdriver.common.by import ID

D. from selenium.webdriver import By

Solution

1. Step 1: Identify the correct import path

   The By class is located in selenium.webdriver.common.by module.

2. Step 2: Validate options

   from selenium.webdriver.common.by import By correctly imports By. import selenium.webdriver.By as By uses invalid syntax. from selenium.webdriver.common.by import ID tries to import ID which doesn't exist. from selenium.webdriver import By imports By from wrong module.

3. Final Answer:

   from selenium.webdriver.common.by import By -> Option A

4. Quick Check:

   Import By from common.by [OK]

Hint: Import By from selenium.webdriver.common.by [OK]

Common Mistakes:

• Trying to import ID instead of By
• Incorrect module path for By
• Using alias import incorrectly

3. What will be the output of the following code snippet if the element with ID 'submit-btn' exists on the page?

from selenium import webdriver
from selenium.webdriver.common.by import By

driver = webdriver.Chrome()
element = driver.find_element(By.ID, "submit-btn")
print(element.tag_name)

medium

A. Prints the tag name of the element with ID 'submit-btn'

B. Throws NoSuchElementException

C. Prints 'submit-btn'

D. SyntaxError due to wrong method

Solution

1. Step 1: Understand find_element behavior

   If the element with ID 'submit-btn' exists, find_element returns the WebElement object.

2. Step 2: Check what element.tag_name returns

   The tag_name attribute returns the HTML tag name of the found element, e.g., 'button' or 'input'.

3. Final Answer:

   Prints the tag name of the element with ID 'submit-btn' -> Option A

4. Quick Check:

   find_element returns element; tag_name prints tag [OK]

Hint: tag_name shows element's HTML tag [OK]

Common Mistakes:

• Assuming print shows the ID instead of tag
• Expecting exception when element exists
• Confusing method names

4. Identify the error in the following code snippet:

from selenium import webdriver
from selenium.webdriver.common.by import By

driver = webdriver.Chrome()
element = driver.find_element(By.id, "username")

medium

A. Missing parentheses after webdriver.Chrome

B. No error, code is correct

C. Wrong method name, should be find_element_by_id

D. Incorrect attribute 'By.id' should be 'By.ID'

Solution

1. Step 1: Check attribute case sensitivity

   The By class attributes are uppercase, so it should be By.ID not By.id.

2. Step 2: Verify other parts

   Parentheses after webdriver.Chrome() are present. The method find_element with By.ID is correct syntax.

3. Final Answer:

   Incorrect attribute 'By.id' should be 'By.ID' -> Option D

4. Quick Check:

   By.ID is uppercase [OK]

Hint: By.ID is uppercase, not lowercase [OK]

Common Mistakes:

• Using lowercase 'id' instead of 'ID'
• Confusing method names with deprecated ones
• Forgetting parentheses on webdriver.Chrome

5. You want to find an element by ID but handle the case where the element might not exist without stopping the test. Which code snippet correctly does this?

hard

A. element = driver.find_element(By.ID, "login")
if element is None:
print("Not found")

B. element = driver.find_element(By.ID, "login") if driver else None

C. try:
element = driver.find_element(By.ID, "login")
except NoSuchElementException:
element = None

D. element = driver.find_element(By.ID, "login") or None

Solution

1. Step 1: Understand exception handling in Selenium

   If an element is not found, Selenium raises NoSuchElementException. To avoid test failure, catch this exception.

2. Step 2: Review options for handling missing element

   try: element = driver.find_element(By.ID, "login") except NoSuchElementException: element = None uses try-except to catch the exception and assign None if not found. Other options do not handle exceptions properly.

3. Final Answer:

   try: element = driver.find_element(By.ID, "login") except NoSuchElementException: element = None -> Option C

4. Quick Check:

   Use try-except for missing elements [OK]

Hint: Use try-except to catch NoSuchElementException [OK]

Common Mistakes:

• Not catching exceptions causing test to fail
• Using incorrect conditional expressions
• Assuming find_element returns None if not found