Find element by ID in Selenium Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of finding an element by ID in Selenium?

Finding an element by ID helps locate a unique element on a web page quickly and reliably, as IDs are meant to be unique per page.

beginner

Which Selenium method is used to find an element by its ID in Python?

The method is driver.find_element(By.ID, 'element_id'), where By.ID specifies the locator strategy.

intermediate

Why is using ID locator preferred over other locators when possible?

Because IDs are unique and usually faster to locate, using them reduces test flakiness and improves performance.

beginner

Show a simple Python Selenium code snippet to find an element by ID and click it.

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

# Setup driver
driver = webdriver.Chrome()
driver.get('https://example.com')

# Find element by ID and click
button = driver.find_element(By.ID, 'submit-button')
button.click()

# Close driver
driver.quit()

intermediate

What happens if Selenium cannot find an element by the given ID?

Selenium raises a NoSuchElementException, indicating the element was not found on the page.

Which Selenium method finds an element by ID in Python?

A driver.find_element(By.ID, 'id_value')

B driver.find_element_by_id('id_value')

C driver.find_element(By.CLASS_NAME, 'id_value')

D driver.find_element(By.NAME, 'id_value')

The modern and recommended way is using driver.find_element(By.ID, 'id_value'). The older find_element_by_id is deprecated.

Why is the ID locator preferred in Selenium tests?

A Because IDs are unique and fast to locate

B Because IDs are always visible on the page

C Because IDs can locate multiple elements

D Because IDs are case-insensitive

IDs are unique per page and locating by ID is usually faster and more reliable.

What exception does Selenium raise if an element by ID is not found?

A InvalidSelectorException

B NoSuchElementException

C TimeoutException

D ElementNotVisibleException

If the element is not found, Selenium raises NoSuchElementException.

Which import is necessary to use By.ID in Selenium Python?

A from selenium.webdriver.chrome.service import Service

B from selenium.webdriver.common.keys import Keys

C from selenium.webdriver.support.ui import WebDriverWait

D from selenium.webdriver.common.by import By

The By class is imported from selenium.webdriver.common.by.

What is the correct way to click an element found by ID 'login'?

A driver.click_element('login')

B driver.find_element_by_id('login').submit()

C driver.find_element(By.ID, 'login').click()

D driver.find_element(By.CLASS_NAME, 'login').click()

You find the element by ID and then call click() on it.

Explain how to find an element by ID using Selenium in Python and why it is useful.

Think about the locator method and its advantages.

Describe what happens if Selenium cannot find an element by the given ID during test execution.

Consider error handling in Selenium tests.

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