Browser options and capabilities in Selenium Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Selenium browser options code?

Consider the following Python Selenium code snippet that sets Chrome options. What will be printed when the code runs?

Selenium Python

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

options = Options()
options.add_argument('--headless')
options.add_argument('--disable-gpu')
driver = webdriver.Chrome(options=options)
print(driver.capabilities.get('headless'))
driver.quit()

A None

B True

C KeyError

D False

💡 Hint

Check how the headless argument affects the capabilities dictionary.

When Chrome is launched with the '--headless' option, the capabilities dictionary includes 'headless': True. So printing driver.capabilities.get('headless') outputs True.

❓ assertion

intermediate

Which assertion correctly verifies the browser is running in incognito mode?

You want to check if Chrome is running in incognito mode using Selenium Python. Which assertion correctly verifies this?

Selenium Python

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

options = Options()
options.add_argument('--incognito')
driver = webdriver.Chrome(options=options)

# Which assertion below is correct?

A assert '--incognito' in driver.capabilities['goog:chromeOptions']['args']

B assert 'incognito' in driver.capabilities['browserName']

C assert driver.capabilities['incognito'] == True

D assert driver.capabilities['chromeOptions']['incognito'] is not None

💡 Hint

Check where Chrome options arguments are stored in capabilities.

The incognito mode is passed as an argument in 'goog:chromeOptions' under 'args'. So checking if '--incognito' is in that list is the correct way.

🔧 Debug

advanced

Why does this Selenium code fail to set the user agent?

The following code tries to set a custom user agent in Chrome but it does not work. What is the reason?

Selenium Python

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

options = Options()
options.add_argument('user-agent=MyCustomAgent/1.0')
driver = webdriver.Chrome(options=options)
print(driver.execute_script('return navigator.userAgent;'))
driver.quit()

A Missing double dashes before 'user-agent' argument; should be '--user-agent=MyCustomAgent/1.0'

B User agent cannot be set via Chrome options; must use capabilities instead

C The argument should be passed as options.set_capability('userAgent', 'MyCustomAgent/1.0')

D The user agent string is ignored if headless mode is not enabled

💡 Hint

Check the syntax of Chrome command line arguments.

Chrome command line arguments require two dashes '--' before the argument name. Missing them causes the argument to be ignored.

🧠 Conceptual

advanced

What is the main purpose of browser capabilities in Selenium?

Choose the best description of the main purpose of browser capabilities in Selenium WebDriver.

A To store test results and logs during test execution

B To define the test case steps and assertions

C To specify browser-specific settings and features before launching the browser

D To manage network traffic and proxy settings only

💡 Hint

Think about what capabilities configure before the browser starts.

Capabilities tell Selenium how to start the browser with specific settings like headless mode, proxy, or extensions.

❓ framework

expert

How to correctly combine Chrome options and capabilities in Selenium Python?

You want to run Chrome in headless mode and set a proxy using Selenium Python. Which code snippet correctly combines Chrome options and capabilities?

A

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

options = Options()
options.add_argument('--headless')
options.add_argument('--proxy-server=http://proxy.example.com:8080')
driver = webdriver.Chrome(options=options)

B

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

options = Options()
options.add_argument('--headless')
capabilities = webdriver.DesiredCapabilities.CHROME.copy()
capabilities['proxy'] = {'proxyType': 'manual', 'httpProxy': 'proxy.example.com:8080'}
driver = webdriver.Chrome(options=options, desired_capabilities=capabilities)

C

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

options = Options()
options.add_argument('--headless')
capabilities = webdriver.DesiredCapabilities.CHROME.copy()
capabilities['proxy'] = {'proxyType': 'manual', 'httpProxy': 'proxy.example.com:8080'}
driver = webdriver.Chrome(desired_capabilities=capabilities)

D

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

options = Options()
options.add_argument('--headless')
options.set_capability('proxy', {'proxyType': 'manual', 'httpProxy': 'proxy.example.com:8080'})
driver = webdriver.Chrome(options=options)

💡 Hint

Check how to set proxy with Chrome options in Selenium Python 4+.

In Selenium Python 4+, the recommended way is to set proxy via options.set_capability, combining options and capabilities cleanly.

Practice

1. What is the main purpose of using Options in Selenium WebDriver for browsers?

easy

A. To customize browser settings like headless mode or window size

B. To write test assertions for page elements

C. To locate elements on a web page

D. To generate test reports automatically

Solution

1. Step 1: Understand what Options configure

   Options allow you to set how the browser behaves during tests, such as running headless or setting window size.

2. Step 2: Differentiate Options from other tasks

   Options do not handle locating elements, assertions, or reports; those are separate tasks.

3. Final Answer:

   To customize browser settings like headless mode or window size -> Option A

4. Quick Check:

   Options = Browser customization [OK]

Hint: Options control browser behavior, not test logic [OK]

Common Mistakes:

• Confusing Options with element locators
• Thinking Options generate reports
• Mixing Options with assertion logic

2. Which of the following is the correct way to set Chrome to run in headless mode using Selenium in Python?

easy

A. options = webdriver.ChromeOptions()
options.add_argument('--headless')

B. options = webdriver.ChromeOptions()
options.set_headless(True)

C. options = webdriver.ChromeOptions()
options.headless = True

D. options = webdriver.ChromeOptions()
options.add_option('headless')

Solution

1. Step 1: Recall correct method to add arguments

   In Selenium Python, add_argument is used to add command line switches like '--headless'.

2. Step 2: Check each option's syntax

   Only options = webdriver.ChromeOptions() options.add_argument('--headless') uses add_argument('--headless') correctly; others use invalid or non-existent methods.

3. Final Answer:

   options = webdriver.ChromeOptions() options.add_argument('--headless') -> Option A

4. Quick Check:

   Use add_argument('--headless') for headless mode [OK]

Hint: Use add_argument('--headless') to enable headless mode [OK]

Common Mistakes:

• Using non-existent set_headless method
• Assigning headless attribute directly
• Using add_option instead of add_argument

3. What will be the effect of the following Python Selenium code snippet?

from selenium import webdriver
options = webdriver.FirefoxOptions()
options.set_preference('dom.webnotifications.enabled', False)
driver = webdriver.Firefox(options=options)
driver.get('https://example.com')

medium

A. Code will raise an error due to invalid method

B. Firefox will launch but notifications will still appear

C. Firefox will launch with notifications disabled on the page

D. Firefox will launch in headless mode

Solution

1. Step 1: Understand set_preference usage

   The method set_preference sets Firefox preferences; here it disables web notifications.

2. Step 2: Analyze the effect on browser behavior

   Passing these options to Firefox disables notifications on pages, so no pop-ups appear.

3. Final Answer:

   Firefox will launch with notifications disabled on the page -> Option C

4. Quick Check:

   set_preference disables notifications [OK]

Hint: set_preference disables features like notifications [OK]

Common Mistakes:

• Assuming notifications still appear
• Confusing set_preference with add_argument
• Thinking code runs headless by default

4. Identify the error in this Selenium Python code snippet that tries to disable browser notifications in Chrome:

from selenium import webdriver
options = webdriver.ChromeOptions()
options.set_preference('profile.default_content_setting_values.notifications', 2)
driver = webdriver.Chrome(options=options)

medium

A. The value 2 is invalid for disabling notifications

B. set_preference is not a method of ChromeOptions

C. Options must be passed as capabilities, not options

D. ChromeOptions cannot disable notifications

Solution

1. Step 1: Check ChromeOptions methods

   ChromeOptions does not have a method called set_preference; this is Firefox-specific.

2. Step 2: Correct way to disable notifications in Chrome

   Chrome uses add_experimental_option with 'prefs' dictionary to disable notifications.

3. Final Answer:

   set_preference is not a method of ChromeOptions -> Option B

4. Quick Check:

   Use add_experimental_option for Chrome prefs [OK]

Hint: ChromeOptions uses add_experimental_option, not set_preference [OK]

Common Mistakes:

• Using Firefox methods on ChromeOptions
• Passing wrong values for notification settings
• Confusing options with capabilities

5. You want to run Chrome in headless mode, disable notifications, and accept insecure certificates using Selenium in Python. Which code snippet correctly sets all these options?

hard

A. options = webdriver.ChromeOptions()
options.headless = True
options.add_experimental_option('prefs', {'notifications': 0})
options.set_capability('acceptInsecureCerts', False)
driver = webdriver.Chrome(options=options)

B. options = webdriver.ChromeOptions()
options.add_argument('headless')
options.set_preference('notifications', False)
options.set_capability('acceptInsecureCerts', True)
driver = webdriver.Chrome(options=options)

C. options = webdriver.ChromeOptions()
options.add_argument('--headless')
options.add_argument('--disable-notifications')
options.accept_insecure_certs = True
driver = webdriver.Chrome(options=options)

D. options = webdriver.ChromeOptions()
options.add_argument('--headless')
options.add_experimental_option('prefs', {'profile.default_content_setting_values.notifications': 2})
options.set_capability('acceptInsecureCerts', True)
driver = webdriver.Chrome(options=options)

Solution

1. Step 1: Set headless mode correctly

   Use add_argument('--headless') to enable headless mode in ChromeOptions.

2. Step 2: Disable notifications properly

   Use add_experimental_option('prefs', {'profile.default_content_setting_values.notifications': 2}) to disable notifications.

3. Step 3: Accept insecure certificates

   Set capability acceptInsecureCerts to True using set_capability.

4. Final Answer:

   options = webdriver.ChromeOptions() options.add_argument('--headless') options.add_experimental_option('prefs', {'profile.default_content_setting_values.notifications': 2}) options.set_capability('acceptInsecureCerts', True) driver = webdriver.Chrome(options=options) -> Option D

5. Quick Check:

   Combine add_argument, add_experimental_option, set_capability [OK]

Hint: Use add_argument, add_experimental_option, set_capability together [OK]

Common Mistakes:

• Missing '--' in headless argument
• Using set_preference on ChromeOptions
• Setting acceptInsecureCerts to False by mistake