[Solved] Consider this Python code snippet configuring a Firefox profile: from selenium.webdriver.firefox.firefox_profile import FirefoxProfile profile = FirefoxProfile() profile.set_preference('browser.... | Selenium Python

Selenium Python - Advanced Patterns

Consider this Python code snippet configuring a Firefox profile:

from selenium.webdriver.firefox.firefox_profile import FirefoxProfile
profile = FirefoxProfile()
profile.set_preference('browser.startup.homepage', 'https://example.com')
profile.set_preference('dom.webnotifications.enabled', False)
profile.update_preferences()

print(profile.default_preferences['browser.startup.homepage'])

What will be printed when this code runs?

Ahttps://example.com

BNone

CKeyError

Dabout:blank

Step-by-Step Solution

Solution:

Step 1: Understand FirefoxProfile attributes
The default_preferences attribute is internal and not updated by set_preference. It may not contain the key.
Step 2: Predict print behavior
Accessing profile.default_preferences['browser.startup.homepage'] will raise a KeyError because this key is not in default_preferences.
Final Answer:
KeyError -> Option C
Quick Check:
Accessing missing key = KeyError [OK]

Quick Trick: Access only updated prefs, not default_preferences dict [OK]

Common Mistakes:

Assuming set_preference updates default_preferences
Expecting print to show new homepage URL
Ignoring that KeyError occurs on missing dict key

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More Selenium Python Quizzes

Consider this Python code snippet configuring a Firefox profile:

Step 1: Understand FirefoxProfile attributes

Step 2: Predict print behavior

Final Answer:

Quick Check:

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