Element locators in page class in Selenium Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ locator

intermediate

Identify the best locator for a login button

You have a login button with HTML: <button id='loginBtn' class='btn primary'>Login</button>. Which locator is the most reliable and efficient to use in a Selenium page class?

A driver.find_element(By.XPATH, "//button[text()='Login']")

B driver.find_element(By.CLASS_NAME, 'btn')

C driver.find_element(By.ID, 'loginBtn')

D driver.find_element(By.CSS_SELECTOR, 'button.primary')

💡 Hint

Think about uniqueness and speed of locating elements.

Using By.ID is the fastest and most reliable because IDs are unique on the page. Class names or CSS selectors might match multiple elements, and XPath is slower.

❓ assertion

intermediate

Choose the correct assertion for verifying page title

You want to check if the page title is exactly 'Welcome Page' after login. Which assertion is correct in a Python unittest test case?

A self.assertEqual(driver.title, 'Welcome Page')

B self.assertTrue(driver.title == 'Welcome Page')

C self.assertIn('Welcome', driver.title)

D self.assertIs(driver.title, 'Welcome Page')

💡 Hint

Check which assertion method compares values for equality properly.

assertEqual checks if two values are exactly equal. assertTrue works but is less clear. assertIn only checks substring presence. assertIs checks object identity, not value equality.

❓ Predict Output

advanced

What is the output of this Selenium locator code?

Given the following page class snippet, what will print(len(page.buttons)) output if the page has 3 buttons with class 'btn'?

Selenium Python

from selenium.webdriver.common.by import By

class Page:
    def __init__(self, driver):
        self.driver = driver
    
    @property
    def buttons(self):
        return self.driver.find_elements(By.CLASS_NAME, 'btn')

# Assume driver is a Selenium WebDriver instance with 3 buttons having class 'btn'
page = Page(driver)
print(len(page.buttons))

A Raises NoSuchElementException

B 1

C 0

D 3

💡 Hint

Remember that find_elements returns a list of matching elements.

find_elements returns a list of all matching elements. Since there are 3 buttons with class 'btn', the length is 3. It does not raise an exception if no elements are found; it returns an empty list.

🔧 Debug

advanced

Find the error in this page class locator

What is wrong with this locator in the page class?

Selenium Python

from selenium.webdriver.common.by import By

class LoginPage:
    def __init__(self, driver):
        self.driver = driver
    
    username_input = (By.ID, 'username')
    
    def enter_username(self, name):
        self.driver.find_element(*self.username_input).send_keys(name)

A No error, code works fine

B find_element expects two arguments, not a tuple

C send_keys is called on a tuple, not a WebElement

D username_input should be a method, not a tuple

💡 Hint

Check how find_element is called with locators.

find_element requires two arguments: locator strategy and locator value. Passing a tuple as a single argument causes a TypeError. The correct call is find_element(*self.username_input) to unpack the tuple.

❓ framework

expert

Which test framework feature best supports page class locators?

In a Selenium test suite using Python, which feature of the pytest framework helps manage page class locators efficiently and promotes clean test code?

A Using pytest fixtures to initialize page objects

B Using pytest.mark.parametrize to test multiple locators

C Using pytest.raises to catch locator errors

D Using pytest.skip to ignore locator tests

💡 Hint

Think about how to reuse page objects across tests.

Pytest fixtures allow setup code to create and provide page objects with locators to tests, promoting reuse and clean code. Parametrize is for data-driven tests, raises is for exception testing, skip is for ignoring tests.