Running tests on Grid in Selenium Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of Selenium Grid test session initialization

What will be the output of this Selenium Python code snippet when connecting to a Selenium Grid hub?

Selenium Python

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.chrome.options import Options

options = Options()
options.add_argument('--headless')

driver = webdriver.Remote(
    command_executor='http://localhost:4444/wd/hub',
    options=options
)
driver.get('https://example.com')
title = driver.title
driver.quit()
print(title)

A Example Domain

B selenium.common.exceptions.WebDriverException: Message: unknown error: cannot find Chrome binary

C selenium.common.exceptions.SessionNotCreatedException: Could not start a new session

D selenium.common.exceptions.InvalidArgumentException: invalid argument: 'options' must be a dictionary

💡 Hint

Think about what the title of https://example.com is and what happens when the Remote WebDriver connects successfully.

The code connects to a Selenium Grid hub at localhost:4444 and opens https://example.com in headless Chrome. The page title is 'Example Domain'. If the Grid and browser nodes are correctly set up, the output is 'Example Domain'. Other options represent common errors if setup is wrong.

❓ assertion

intermediate

Correct assertion for page title in Selenium Grid test

Which assertion correctly verifies that the page title is exactly 'Welcome Page' after loading a page using Selenium Grid in Python?

Selenium Python

driver.get('https://myapp.com/welcome')
page_title = driver.title

A assert page_title == 'Welcome Page'

B assert 'Welcome' in page_title

C assert page_title.startswith('Welcome')

D assert page_title != 'Welcome Page'

💡 Hint

The question asks for exact match, not partial or negation.

Option A checks for exact equality, which matches the requirement. Options B and C check partial matches, and D is the opposite of what is needed.

❓ locator

advanced

Best locator strategy for Selenium Grid test

You want to locate a login button with text 'Log In' on a page loaded via Selenium Grid. Which locator is the best practice for reliability and speed?

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

B driver.find_element(By.CSS_SELECTOR, "button.login-btn")

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

D driver.find_element(By.ID, "loginButton")

💡 Hint

IDs are unique and fastest locators if available.

Using By.ID is the fastest and most reliable locator if the element has a unique ID. Other locators may be slower or less reliable if classes or text change.

🔧 Debug

advanced

Identify the cause of session creation failure on Selenium Grid

Given this Python Selenium code connecting to a Grid, the test fails with 'SessionNotCreatedException'. What is the most likely cause?

Selenium Python

from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.add_argument('--headless')

driver = webdriver.Remote(
    command_executor='http://localhost:4444/wd/hub',
    options=options
)
driver.get('https://example.com')

A The options argument is not supported by Remote WebDriver

B The Selenium Grid hub is not running or unreachable at the given URL

C The Chrome browser binary is missing on the node machine

D The URL 'https://example.com' is invalid

💡 Hint

SessionNotCreatedException often means the browser could not start on the node.

If the Chrome binary is missing on the node, the Grid cannot start a browser session, causing SessionNotCreatedException. Hub not running causes connection errors, not session creation errors. Options argument is supported. The URL is valid.

❓ framework

expert

Parallel test execution strategy on Selenium Grid with pytest

You want to run 5 Selenium tests in parallel on a Selenium Grid using pytest. Which pytest command and configuration correctly achieves this?

A pytest --max-workers=5 --selenium-grid-url=http://localhost:4444/wd/hub

B pytest -n 5 --dist=loadscope --maxfail=1

C pytest -n 5 --dist=loadfile

D pytest --parallel=5 --grid-url=http://localhost:4444

💡 Hint

pytest-xdist plugin uses -n to specify number of parallel workers.

Option B uses pytest-xdist's -n 5 to run 5 tests in parallel with loadscope distribution. Other options use invalid or non-existent pytest flags.