Parameterize with test data in Selenium Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the pytest module needed for parameterization.

Selenium Python

import [1]

Drag options to blanks, or click blank then click option'

Apytest

Bselenium

Crequests

Dunittest

Attempts:

3 left

💡 Hint

Common Mistakes

Importing unittest instead of pytest

Forgetting to import any testing module

We use pytest to enable parameterized tests in Python.

2fill in blank

medium

Complete the code to add the pytest decorator for parameterizing the test with two inputs.

Selenium Python

@pytest.mark.[1]("input,expected")
def test_example(input, expected):
    assert input + 1 == expected

Drag options to blanks, or click blank then click option'

Afixture

Bskip

Cmark

Dparametrize

Attempts:

3 left

💡 Hint

Common Mistakes

Using @pytest.mark.fixture instead

Misspelling the decorator name

The @pytest.mark.parametrize decorator allows running the test with different inputs.

3fill in blank

hard

Fix the error in the parameterized test data format by completing the code.

Selenium Python

@pytest.mark.parametrize("input,expected", [
    (1, 2),
    (2, [1]),
    (3, 4)
])
def test_add_one(input, expected):
    assert input + 1 == expected

Drag options to blanks, or click blank then click option'

A5

B3

C2

D4

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong expected values that do not match input + 1

Syntax errors in the list of tuples

The expected value for input 2 should be 3, since 2 + 1 = 3.

4fill in blank

hard

Fill both blanks to create a parameterized test that checks if a string contains a substring.

Selenium Python

@pytest.mark.parametrize("text,substring")
def test_contains(text, substring):
    assert [1] in [2]

Drag options to blanks, or click blank then click option'

Asubstring

Btext

Attempts:

3 left

💡 Hint

Common Mistakes

Reversing the order of substring and text

Using equality instead of 'in'

The test checks if the substring is inside the text, so substring in text is correct.

5fill in blank

hard

Fill all three blanks to create a parameterized test that checks if a number is within a range.

Selenium Python

@pytest.mark.parametrize("num,low,high")
def test_in_range(num, low, high):
    assert [1] <= [2] <= [3]

Drag options to blanks, or click blank then click option'

Alow

Bnum

Chigh

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping num with low or high

Using separate comparisons instead of chained

The test asserts that num is between low and high, so the correct order is low <= num <= high.

Practice

1. What is the main purpose of using @pytest.mark.parametrize in Selenium Python tests?

easy

A. To run tests in parallel threads

B. To skip tests that are not ready

C. To run the same test function multiple times with different input data

D. To generate HTML reports automatically

Solution

1. Step 1: Understand the decorator's role

   @pytest.mark.parametrize allows running one test function multiple times with different sets of input data.

2. Step 2: Compare with other options

   Skipping tests, running in parallel, or generating reports are different pytest features, not related to parameterization.

3. Final Answer:

   To run the same test function multiple times with different input data -> Option C

4. Quick Check:

   Parameterize = run test with many inputs [OK]

Hint: Parameterize means run test repeatedly with different data [OK]

Common Mistakes:

• Confusing parameterize with skipping tests
• Thinking it runs tests in parallel
• Assuming it generates reports

2. Which of the following is the correct syntax to parameterize a test function with two sets of inputs ("user1", "pass1") and ("user2", "pass2") in pytest?

easy

A. @pytest.parametrize('username', ['user1', 'user2'], 'password', ['pass1', 'pass2'])

B. @pytest.mark.parametrize('username, password', [('user1', 'pass1'), ('user2', 'pass2')])

C. @pytest.mark.parametrize(['username', 'password'], 'user1', 'pass1', 'user2', 'pass2')

D. @pytest.mark.parametrized('username', 'password', [('user1', 'pass1'), ('user2', 'pass2')])

Solution

1. Step 1: Recall correct decorator syntax

   The correct syntax uses @pytest.mark.parametrize with a string of parameter names and a list of tuples for values.

2. Step 2: Identify correct option

   @pytest.mark.parametrize('username, password', [('user1', 'pass1'), ('user2', 'pass2')]) matches the correct syntax exactly. Other options have wrong method names or argument formats.

3. Final Answer:

   @pytest.mark.parametrize('username, password', [('user1', 'pass1'), ('user2', 'pass2')]) -> Option B

4. Quick Check:

   Parametrize('params', [tuples]) = correct syntax [OK]

Hint: Use string param names and list of tuples for values [OK]

Common Mistakes:

• Misspelling 'parametrize' as 'parametrized' or 'parametrize'
• Passing parameters as separate lists instead of tuples
• Using wrong decorator name

3. Given the following test code, what will be the output when running the test?

import pytest

@pytest.mark.parametrize('num, expected', [(1, 2), (3, 4)])
def test_increment(num, expected):
    assert num + 1 == expected

medium

A. First test fails, second test passes

B. Both tests fail

C. First test passes, second test fails

D. Both tests pass

Solution

1. Step 1: Analyze each test case

   For (1, 2): 1 + 1 = 2, assertion passes. For (3, 4): 3 + 1 = 4, assertion passes.

2. Step 2: Determine overall result

   Since both assertions pass, both tests pass successfully.

3. Final Answer:

   Both tests pass -> Option D

4. Quick Check:

   num+1 == expected for all inputs [OK]

Hint: Check each input pair separately for assertion [OK]

Common Mistakes:

• Assuming one test fails without checking values
• Confusing expected values with actual calculation
• Ignoring that both inputs are tested

4. Identify the error in the following parameterized test code:

import pytest

@pytest.mark.parametrize('username, password')
def test_login(username, password):
    assert username != '' and password != ''

medium

A. Missing list of parameter values in @pytest.mark.parametrize decorator

B. Function parameters do not match decorator parameters

C. Assertion logic is incorrect

D. pytest module is not imported

Solution

1. Step 1: Check decorator usage

   The decorator @pytest.mark.parametrize requires two arguments: parameter names and a list of values. Here, the list of values is missing.

2. Step 2: Verify other parts

   Function parameters match decorator names, assertion logic is valid, and pytest is imported correctly.

3. Final Answer:

   Missing list of parameter values in @pytest.mark.parametrize decorator -> Option A

4. Quick Check:

   Parametrize needs names and values [OK]

Hint: Always provide parameter values list with parametrize [OK]

Common Mistakes:

• Forgetting the list of test data tuples
• Mismatching parameter names and function arguments
• Incorrect assertion logic

5. You want to test a login form with multiple username and password pairs using Selenium and pytest. Which approach correctly applies parameterization and Selenium WebDriver usage together?

hard

A. Use @pytest.mark.parametrize to pass username and password, then inside the test open the browser, enter credentials, and assert login success

B. Write separate test functions for each username and password pair without parameterization

C. Use a loop inside a single test function to iterate over username and password pairs without parameterization

D. Use @pytest.mark.parametrize but open the browser only once outside the test function

Solution

1. Step 1: Understand parameterization with Selenium

   Parameterization with @pytest.mark.parametrize allows running the test multiple times with different data, opening the browser fresh each time ensures test isolation.

2. Step 2: Evaluate other options

   Writing separate tests duplicates code, looping inside one test loses pytest reporting benefits, and opening browser only once risks test interference.

3. Final Answer:

   Use @pytest.mark.parametrize to pass username and password, then inside the test open the browser, enter credentials, and assert login success -> Option A

4. Quick Check:

   Parametrize + fresh browser per test = best practice [OK]

Hint: Parametrize inputs and open browser inside test for isolation [OK]

Common Mistakes:

• Opening browser once for all tests causing state issues
• Not using parameterize and duplicating test code
• Using loops inside tests instead of parameterize