CSS pseudo-classes for selection in Selenium Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a CSS pseudo-class?

A CSS pseudo-class is a keyword added to selectors that specifies a special state of the selected elements, like :hover for when a mouse is over an element.

beginner

How can you select the first child of a parent element using CSS pseudo-classes?

Use the :first-child pseudo-class to select the first child element of its parent.

intermediate

In Selenium with Python, how do you use a CSS pseudo-class in a locator?

You can use driver.find_element(By.CSS_SELECTOR, 'tag:pseudo-class') to locate elements matching the pseudo-class, for example, 'li:first-child'.

intermediate

What does the :nth-child(n) pseudo-class do?

It selects the nth child element of its parent, where n can be a number, keyword, or formula.

intermediate

Why should you prefer CSS pseudo-classes over XPath in Selenium for some selections?

CSS selectors with pseudo-classes are often faster and simpler for selecting elements based on position or state, improving test speed and readability.

Which CSS pseudo-class selects an element when the mouse pointer is over it?

A :hover

B :active

C :focus

D :visited

The :hover pseudo-class applies when the mouse pointer is over an element.

How would you select the third child of a list using CSS pseudo-classes?

A :only-child

B :last-child

C :first-child

D :nth-child(3)

:nth-child(3) selects the third child element.

In Selenium Python, which method is used to locate elements by CSS selector?

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

B driver.find_element(By.CSS_SELECTOR, 'selector')

C driver.find_element(By.XPATH, 'selector')

D driver.find_element(By.CLASS_NAME, 'selector')

Use By.CSS_SELECTOR to locate elements with CSS selectors.

Which pseudo-class selects an element that is the only child of its parent?

A :only-child

B :first-child

C :last-child

D :nth-child(1)

:only-child selects an element that is the only child of its parent.

Why might CSS pseudo-classes be preferred over XPath in Selenium tests?

A They are slower but more readable

B XPath does not support pseudo-classes

C They are faster and simpler for certain selections

D CSS selectors cannot select by position

CSS selectors with pseudo-classes are often faster and simpler for selecting elements by position or state.

Explain how CSS pseudo-classes can help select elements in Selenium tests.

Think about how you pick elements based on their state or position.

Describe the difference between :first-child and :nth-child(n) pseudo-classes.

Consider how you pick the first item versus any specific item.