Data providers pattern in Selenium Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of test execution with data provider

Given the following Selenium test code using a data provider pattern, what will be the output when running the test?

Selenium Python

import unittest
from parameterized import parameterized

class TestLogin(unittest.TestCase):

    @parameterized.expand([
        ("user1", "pass1"),
        ("user2", "pass2"),
        ("user3", "pass3")
    ])
    def test_login(self, username, password):
        print(f"Testing login with {username} and {password}")
        self.assertTrue(len(username) > 0)
        self.assertTrue(len(password) > 0)

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

A Three tests run, but all fail due to assertion error

B One test runs, printing 'Testing login with user1 and pass1', passes

C Three tests run, each printing 'Testing login with userX and passX', all pass

D Test fails to run due to missing data provider decorator

💡 Hint

Look at how many parameter sets are provided to the @parameterized.expand decorator.

The @parameterized.expand decorator runs the test method once for each tuple in the list. Each test prints the username and password and asserts their length is greater than zero, so all pass.

❓ assertion

intermediate

Correct assertion for data-driven test

In a data-driven Selenium test, which assertion correctly verifies that the page title contains the expected keyword for each data set?

Selenium Python

def test_page_title(self, keyword):
    title = self.driver.title
    # Which assertion is correct here?

A self.assertFalse(keyword in title)

B self.assertIn(keyword, title)

C self.assertEqual(keyword, title)

D self.assertTrue(title.startswith(keyword))

💡 Hint

We want to check if the keyword appears anywhere in the title.

assertIn checks if the keyword is part of the title string, which is the intended verification. assertEqual would require exact match, which is too strict.

❓ locator

advanced

Best locator strategy for data-driven tests

In a data-driven Selenium test, you need to locate a button whose text changes based on test data. Which locator strategy is best to use?

A Locate by XPath using contains(text(), variable_text)

B Locate by fixed ID attribute

C Locate by CSS class name

D Locate by tag name only

💡 Hint

The button text changes per test data, so the locator must adapt dynamically.

Using XPath with contains(text(), variable_text) allows locating elements based on dynamic text content, which fits data-driven tests where text varies.

🔧 Debug

advanced

Debugging failing data-driven test

A data-driven Selenium test fails intermittently with a NoSuchElementException on a locator that worked before. What is the most likely cause?

A The page content changes based on test data, so the element is missing for some inputs

B The locator syntax is invalid and causes a runtime error

C The test data provider is empty, so no tests run

D The browser driver is not installed

💡 Hint

Think about how test data can affect page elements.

If the page changes depending on input data, some elements may not appear, causing NoSuchElementException only for certain data sets.

❓ framework

expert

Implementing data providers in pytest for Selenium

Which pytest feature allows you to implement data providers for Selenium tests to run the same test with multiple data sets?

A unittest.TestCase subclass with setUp method

B Using Selenium WebDriverWait explicitly

C pytest.fixture with scope='module'

D @pytest.mark.parametrize decorator

💡 Hint

Look for a pytest decorator that runs tests multiple times with different inputs.

The @pytest.mark.parametrize decorator runs a test function multiple times with different argument values, acting as a data provider.