WebDriver API Structure

WebDriver provides a comprehensive class library with two core functions:

• Element discovery
• Element manipulation

Installation Commands

pip install selenium==3.14.0
pip uninstall selenium
pip show selenium

Automation Testing Workflow

1. Import required packages
2. Instantiate browser driver
3. Navigate to target application
4. Locate elements
5. Perform actions on elements
6. Implement waits
7. Close browser

Handling File Paths

Different approaches for specifying local file paths:

# Escaped backslashes
url = "E:\\Users\\test.html"

# Raw string notation
url = r"E:\Users\test.html"

# Forward slash format
url = "file:///E:/Users/test.html"

Note: Backslashes serve as escape characters in Python strings, so double-escaping or raw strings are necessary.

Element Location Strategies

By ID

Locates elemetns using the id attribute. Most reliable when available.

element = driver.find_element(By.ID, "submit-btn")

By Name

Targets elements via the name attribute.

element = driver.find_element(By.NAME, "username")

By Class Name

Finds elements matching a specific class attribute.

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

By Tag Name

Selects elements by their HTML tag. Returns the first matchign element if multiple exist.

element = driver.find_element(By.TAG_NAME, "input")

By Link Text

Exclusive to anchor (<a>) elements. Requires exact text matching.

element = driver.find_element(By.LINK_TEXT, "Click here for details")

By Partial Link Text

Matches anchor elements using partial text. Useful for dynamic content.

element = driver.find_element(By.PARTIAL_LINK_TEXT, "details")

Note: The find_elements_by_* methods return a list. Access elements using index notation.

elements = driver.find_elements(By.TAG_NAME, "a")
first_link = elements[0]

XPath Expressions

XPath provides flexible navigation through element hierarchy.

Absolute vs Relative Paths

# Absolute path (not recommended)
/html/body/div[2]/form/input[1]

# Relative path (preferred)
//input[@id='search']

Element Attribute Matching

//span[contains(text(),'CompanyName')]
//span[text()='CompanyName']
//div[@class="u_sp"]

Combining Attributes with Logical Operators

//div[@class="container" and @name='header']

Position-Based Selection

//book[last()]
//book[last()-1]

Advanced Attribute Functions

//*[contains(@id,'user')]
//*[starts-with(@class,'btn-')]

CSS Selectors

CSS provides concise and performant element selection.

Locator Type	Syntax	Example
ID	#id	#main-content
Class	.class	.btn-submit
Element	element	input
Attribute	[attribute=value]	[type='password']
Descendant	ancestor descendant	form input
Child	parent > child	ul > li

Attribute Value Substring Matching

[class^='btn']     /* starts with */
[class$='btn']     /* ends with */
[class*='btn']     /* contains */

Matching Multiple Class Values

driver.find_element_by_css_selector("input[class~='btn']")

Structural Selectors

driver.find_element_by_css_selector("div#nav > a:first-child")
driver.find_element_by_css_selector("div#nav > a:nth-child(2)")
driver.find_element_by_css_selector("div#nav > a:last-child")

# Select the last input within a span
span input:last-child

Note: The :contains() pseudo-class has been deprecated in CSS selectors.

XPath Axes

Axes enable navigation relative to the current node position.

Axis	Description
ancestor	All ancestor nodes (parent, grandparent, etc.)
parent	Direct parenet node only
preceding	All nodes appearing before current element in document
preceding-sibling	Sibling nodes preceding current element
following	All nodes appearing after current element in document
following-sibling	Sibling nodes following current element

//div[@class='content']/ancestor::form
//input[@name='email']/following-sibling::span