XPath with contains and starts-with in Selenium Python - Test Execution Trace

Test Overview

This test opens a webpage and uses XPath with contains() and starts-with() functions to find elements. It verifies that the correct elements are found and their text matches expected values.

Test Code - Selenium

Selenium Python

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
import unittest

class TestXPathFunctions(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Chrome()
        self.driver.get('https://example.com/testpage')

    def test_xpath_contains_and_startswith(self):
        driver = self.driver
        wait = WebDriverWait(driver, 10)

        # Find element where attribute contains 'submit'
        submit_button = wait.until(EC.presence_of_element_located((By.XPATH, "//button[contains(@id, 'submit')]")))
        self.assertEqual(submit_button.text, 'Submit')

        # Find element where attribute starts-with 'user'
        username_input = wait.until(EC.presence_of_element_located((By.XPATH, "//input[starts-with(@name, 'user')]")))
        self.assertEqual(username_input.get_attribute('placeholder'), 'Enter username')

    def tearDown(self):
        self.driver.quit()

if __name__ == '__main__':
    unittest.main()

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Test starts and Chrome browser opens	Browser window is open and ready	—	PASS
2	Browser navigates to 'https://example.com/testpage'	Page loads with test elements visible	—	PASS
3	Wait until button with id containing 'submit' is present using XPath contains()	Button element with id like 'btn-submit' is found	Check button text equals 'Submit'	PASS
4	Wait until input with name starting with 'user' is present using XPath starts-with()	Input element with name like 'username' is found	Check input placeholder attribute equals 'Enter username'	PASS
5	Browser closes and test ends	Browser window closed	—	PASS

Failure Scenario

Failing Condition: Element with XPath using contains() or starts-with() is not found within timeout

Execution Trace Quiz - 3 Questions

Which XPath function is used to find elements with attribute values that include a specific substring?

A contains()

B starts-with()

C ends-with()

D equals()

Key Result

Using XPath functions like contains() and starts-with() helps find elements flexibly by partial attribute matching, making tests more robust to small changes in attribute values.

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