XPath with contains and starts-with in Selenium Python - Framework Patterns

Framework Mode - XPath with contains and starts-with

Folder Structure

selenium_python_project/
├── src/
│   ├── pages/
│   │   └── login_page.py          # Page Object classes with XPath locators
│   ├── tests/
│   │   └── test_login.py           # Test cases using page objects
│   ├── utils/
│   │   └── helpers.py              # Utility functions (e.g., wait helpers)
│   └── config/
│       └── config.yaml             # Environment and browser settings
├── requirements.txt                # Python dependencies
├── pytest.ini                     # Pytest configuration
└── conftest.py                    # Fixtures for setup/teardown
    

Test Framework Layers

• Driver Layer: Manages WebDriver setup and teardown (in conftest.py).
• Page Objects: Classes in src/pages/ define web elements using XPath with contains() and starts-with() for flexible locators.
• Tests: Test scripts in src/tests/ use page objects to perform actions and assertions.
• Utilities: Helper functions for waits, logging, or data handling in src/utils/.
• Configuration: Environment variables, browser options, and credentials stored in src/config/config.yaml.

Configuration Patterns

Use a YAML file (config.yaml) to store environment URLs, browser choices, and credentials. Load this config in conftest.py to initialize WebDriver accordingly.

# Example config.yaml
base_url: "https://example.com"
browser: "chrome"
credentials:
  username: "testuser"
  password: "securepass"
    

This keeps sensitive data separate and allows easy switching between environments.

Test Reporting and CI/CD Integration

• Use pytest with plugins like pytest-html to generate readable HTML reports.
• Integrate tests into CI/CD pipelines (e.g., GitHub Actions, Jenkins) to run tests automatically on code changes.
• Reports help quickly see which XPath locators passed or failed, especially those using contains() and starts-with().

Best Practices

• Use contains() in XPath to locate elements with partial attribute values, making tests resilient to small UI changes.
• Use starts-with() to match elements whose attributes begin with a known string, useful for dynamic IDs.
• Keep XPath expressions readable and maintainable by defining them as variables or constants in page objects.
• Use explicit waits to ensure elements located by XPath are present before interacting.
• Separate locators from test logic by using the Page Object Model for cleaner, reusable code.

Self Check

Where in this framework structure would you add a new XPath locator using contains() for a "Sign Up" button?

Key Result

Use Page Object Model with XPath contains() and starts-with() for flexible, maintainable element locators in Selenium Python tests.

Practice

1. Which XPath function would you use to find an element whose id attribute contains the text "submit" anywhere inside it?

easy

A. starts-with(@id, 'submit')

B. contains(@id, 'submit')

C. ends-with(@id, 'submit')

D. equals(@id, 'submit')

Solution

1. Step 1: Understand the contains() function

   The contains() function checks if an attribute or text includes a specific substring anywhere inside it.

2. Step 2: Apply contains() to the id attribute

   Using contains(@id, 'submit') finds elements where the id attribute has 'submit' anywhere in its value.

3. Final Answer:

   contains(@id, 'submit') -> Option B

4. Quick Check:

   contains() = substring anywhere [OK]

Hint: Use contains() to match substring anywhere in attribute [OK]

Common Mistakes:

• Using starts-with() when substring is not at start
• Using ends-with() which is not supported in XPath 1.0
• Using equals() which requires exact match

2. Which of the following is the correct XPath syntax to select elements whose class attribute starts with "btn-"?

easy

A. //element[@class^='btn-']

B. //element[contains(@class, 'btn-')]

C. //element[starts-with(@class, 'btn-')]

D. //element[@class*='btn-']

Solution

1. Step 1: Identify the correct function for 'starts with'

   The starts-with() function is used to check if an attribute value begins with a specific substring.

2. Step 2: Check XPath syntax

   The correct syntax is //element[starts-with(@class, 'btn-')]. Options C and D use invalid XPath syntax for this purpose.

3. Final Answer:

   //element[starts-with(@class, 'btn-')] -> Option C

4. Quick Check:

   starts-with() = prefix match [OK]

Hint: Use starts-with() for prefix matching in XPath [OK]

Common Mistakes:

• Using contains() instead of starts-with() for prefix
• Using CSS selector syntax like ^= or *= in XPath
• Missing parentheses in function call

3. What will be the result of this XPath query?

//div[contains(text(), 'Error') and starts-with(@class, 'alert-')]

Assuming the HTML contains:

<div class="alert-danger">Error: Invalid input</div>
<div class="alert-success">Success</div>
<div class="message-error">Error occurred</div>

medium

A. Selects only the div with class 'alert-danger'

B. Selects no elements

C. Selects all div elements containing 'Error'

D. Selects the first and second div elements

Solution

1. Step 1: Analyze contains(text(), 'Error')

   This matches div elements whose visible text includes 'Error'. The first and third divs contain 'Error'.

2. Step 2: Analyze starts-with(@class, 'alert-')

   This matches div elements whose class attribute starts with 'alert-'. The first and second divs match this.

3. Step 3: Combine both conditions with AND

   Only the first div satisfies both: text contains 'Error' and class starts with 'alert-'.

4. Final Answer:

   Selects only the div with class 'alert-danger' -> Option A

5. Quick Check:

   AND filters to first div only [OK]

Hint: AND requires both conditions true for selection [OK]

Common Mistakes:

• Assuming contains() matches attribute instead of text
• Ignoring the starts-with() condition
• Selecting all divs with 'Error' ignoring class prefix

4. You wrote this XPath to find buttons starting with "save":

//button[contains(@id, 'save-')]

But it also matches buttons with id "disable-save". How to fix it?

medium

A. //button[starts-with(@id, 'save-')]

B. //button[contains(text(), 'save-')]

C. //button[@id='save-']

D. //button[ends-with(@id, 'save-')]

Solution

1. Step 1: Understand why contains() matches unwanted ids

   contains(@id, 'save-') matches any id containing 'save-' anywhere, including 'disable-save'.

2. Step 2: Use starts-with() to match only ids beginning with 'save-'

   starts-with(@id, 'save-') ensures only ids starting exactly with 'save-' are matched.

3. Final Answer:

   //button[starts-with(@id, 'save-')] -> Option A

4. Quick Check:

   starts-with() fixes unwanted matches [OK]

Hint: Use starts-with() to avoid partial matches inside strings [OK]

Common Mistakes:

• Using contains() when prefix match is needed
• Using ends-with() which XPath 1.0 does not support
• Matching text() instead of attribute

5. You want to select all <a> elements where the href attribute starts with "https://" and the link text contains "Learn". Which XPath expression correctly does this?

hard

A. //a[contains(@href, 'https://') and contains(text(), 'Learn')]

B. //a[contains(text(), 'https://') and starts-with(@href, 'Learn')]

C. //a[starts-with(text(), 'Learn') and contains(@href, 'https://')]

D. //a[starts-with(@href, 'https://') and contains(text(), 'Learn')]

Solution

1. Step 1: Match href attribute starting with 'https://'

   Use starts-with(@href, 'https://') to ensure href begins exactly with 'https://'.

2. Step 2: Match link text containing 'Learn'

   Use contains(text(), 'Learn') to find links whose visible text includes 'Learn' anywhere.

3. Step 3: Combine both conditions with AND

   Both conditions must be true, so use and between them.

4. Final Answer:

   //a[starts-with(@href, 'https://') and contains(text(), 'Learn')] -> Option D

5. Quick Check:

   starts-with() + contains() combined correctly [OK]

Hint: Combine starts-with() for attribute and contains() for text [OK]

Common Mistakes:

• Using contains() for href prefix instead of starts-with()
• Swapping text() and attribute in functions
• Using starts-with() on text when contains() is needed