Test classes in PyTest - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a test class in pytest.

PyTest

class TestExample:
    def [1](self):
        assert 1 + 1 == 2

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

Acheck_add

Baddition_test

Ctest_addition

Dverify_addition

Attempts:

3 left

💡 Hint

Common Mistakes

Not starting the method name with 'test_' so pytest skips the test.

Using a method name that does not follow pytest naming conventions.

The method name must start with test_ for pytest to recognize it as a test.

2fill in blank

medium

Complete the code to use a setup method in a pytest test class.

PyTest

class TestSetup:
    def [1](self):
        self.value = 10

    def test_value(self):
        assert self.value == 10

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

Asetup_method

BsetUp

Csetup_class

Dsetup

Attempts:

3 left

💡 Hint

Common Mistakes

Using setup or setUp which are not recognized by pytest.

Using setup_class which runs once per class, not before each test.

In pytest, setup_method is used to run setup code before each test method.

3fill in blank

hard

Fix the error in the test class to correctly use a class-level setup in pytest.

PyTest

class TestClassSetup:
    @classmethod
    def [1](cls):
        cls.data = [1, 2, 3]

    def test_data_length(self):
        assert len(self.data) == 3

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

AsetupMethod

Bsetup_class

Csetup_class_method

Dsetup

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect method names like setupMethod or setup.

Not using the @classmethod decorator.

The correct class-level setup method name in pytest is setup_class decorated with @classmethod.

4fill in blank

hard

Fill both blanks to correctly skip a test method conditionally in a pytest test class.

PyTest

import pytest

class TestSkip:
    @pytest.mark.[1](reason="Not ready")
    def [2](self):
        assert False

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

Askip

Bskipif

Ctest_skip

Dtest_skip_method

Attempts:

3 left

💡 Hint

Common Mistakes

Using skipif without a condition.

Naming the test method without the test_ prefix.

The decorator @pytest.mark.skip skips the test unconditionally. The test method must start with test_.

5fill in blank

hard

Fill all three blanks to correctly parametrize a test method inside a pytest test class.

PyTest

import pytest

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

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

Aparametrize

Btest_increment

Cinput

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong decorator names like parameterize.

Mismatch between parameter names in decorator and method signature.

Use @pytest.mark.parametrize to run a test with multiple inputs. The test method must start with test_. The parameter name must match the first argument of parametrize.

Practice

1. What is the main purpose of using test classes in pytest?

easy

A. To avoid writing assertions

B. To group related tests for better organization

C. To make tests run faster

D. To skip tests automatically

Solution

1. Step 1: Understand test grouping

   Test classes help organize related test functions together in one place.

2. Step 2: Recognize benefits

   This grouping improves readability and allows shared setup for tests.

3. Final Answer:

   To group related tests for better organization -> Option B

4. Quick Check:

   Test classes group tests = C [OK]

Hint: Test classes group related tests logically [OK]

Common Mistakes:

• Thinking test classes speed up tests
• Believing test classes skip tests
• Assuming test classes remove need for assertions

2. Which of the following is the correct way to name a pytest test class?

easy

A. class testExample:

B. class ExampleTest:

C. class TestExample:

D. class exampleTest:

Solution

1. Step 1: Recall pytest naming rules

   Pytest requires test classes to start with 'Test' exactly.

2. Step 2: Check options

   Only 'TestExample' starts with 'Test' correctly and follows naming conventions.

3. Final Answer:

   class TestExample: -> Option C

4. Quick Check:

   Class name starts with 'Test' = D [OK]

Hint: Test classes must start with 'Test' exactly [OK]

Common Mistakes:

• Starting class name with lowercase 'test'
• Placing 'Test' at the end of class name
• Using mixed case that doesn't start with 'Test'

3. Given the code below, what will pytest report when running these tests?

class TestMath:
    def test_add(self):
        assert 1 + 1 == 2

    def test_subtract(self):
        assert 5 - 3 == 1

medium

A. 1 test passed, 1 test failed

B. 2 tests passed

C. 2 tests failed

D. Syntax error, tests won't run

Solution

1. Step 1: Check each assertion

   test_add asserts 1+1==2 which is True; test_subtract asserts 5-3==1 which is False.

2. Step 2: Determine test results

   One test passes (test_add), one test fails (test_subtract).

3. Final Answer:

   1 test passed, 1 test failed -> Option A

4. Quick Check:

   Assertions true/false = 1 pass, 1 fail [OK]

Hint: Check each assertion result carefully [OK]

Common Mistakes:

• Assuming both tests pass without checking assertions
• Ignoring that 5 - 3 != 1
• Thinking syntax error due to indentation

4. Identify the error in the following pytest test class:

class TestCalc:
    def test_multiply(self):
        assert 2 * 3 == 6
    
    def multiply_test(self):
        assert 4 * 5 == 20

medium

A. Method 'multiply_test' will not be recognized as a test

B. Class name must not start with 'Test'

C. Missing assert statement in 'test_multiply'

D. Indentation error in method definitions

Solution

1. Step 1: Check method naming rules

   Pytest requires test methods to start with 'test_'. 'multiply_test' does not.

2. Step 2: Understand consequences

   Method 'multiply_test' will be ignored by pytest and not run as a test.

3. Final Answer:

   Method 'multiply_test' will not be recognized as a test -> Option A

4. Quick Check:

   Test methods start with 'test_' = A [OK]

Hint: Test methods must start with 'test_' [OK]

Common Mistakes:

• Thinking class name can't start with 'Test'
• Missing assert in test method
• Assuming indentation error without evidence

5. How can you share setup code for all tests inside a pytest test class?

hard

A. Define a method named 'setup_method' inside the class

B. Use a global variable outside the class

C. Write setup code inside each test method separately

D. Define a method named 'setup_class' inside the class

Solution

1. Step 1: Understand pytest setup methods

   Pytest supports 'setup_class' to run setup once for all tests in a class.

2. Step 2: Compare options

   'setup_method' runs before each test method, not once for all; global variables and repeated code are not best practice.

3. Final Answer:

   Define a method named 'setup_class' inside the class -> Option D

4. Quick Check:

   Class-wide setup uses 'setup_class' = B [OK]

Hint: Use 'setup_class' for one-time class setup [OK]

Common Mistakes:

• Confusing 'setup_method' with class-wide setup
• Using global variables instead of setup methods
• Repeating setup code in every test method