Why markers categorize and control tests in PyTest - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to mark the test as slow.

PyTest

import pytest

@pytest.mark.[1]
def test_example():
    assert 1 + 1 == 2

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

Afast

Bslow

Cskip

Dparametrize

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'fast' marker for a slow test.

Confusing 'skip' marker with categorizing tests.

Using 'parametrize' which is for test data, not categorization.

The @pytest.mark.slow marker labels the test as slow, so it can be selected or skipped during test runs.

2fill in blank

medium

Complete the code to skip the test when a condition is true.

PyTest

import pytest

@pytest.mark.skipif([1], reason="Not supported")
def test_feature():
    assert True

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

A1 == 2

BFalse

CTrue

D2 > 3

Attempts:

3 left

💡 Hint

Common Mistakes

Using False which does not skip the test.

Using expressions that evaluate to False.

Confusing skipif condition with test assertions.

The @pytest.mark.skipif(True, reason=...) decorator skips the test unconditionally.

3fill in blank

hard

Fix the error in the marker usage to run tests with the 'network' marker only.

PyTest

# Run tests with pytest -m [1]
pytest

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

A'network'

BNetwork

Cnetwork_tests

Dnetwork

Attempts:

3 left

💡 Hint

Common Mistakes

Using uppercase marker names.

Adding quotes around the marker name.

Using a different marker name than defined.

The marker name is case-sensitive and should be used without quotes in the command line.

4fill in blank

hard

Fill both blanks to mark a test to run only on Linux and skip otherwise.

PyTest

import pytest
import sys

@pytest.mark.skipif(sys.platform != [1], reason="Only Linux")
def test_linux_only():
    assert True

# Run with pytest -m [2]

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

A'linux'

B'win32'

Clinux

Dlinux_only

Attempts:

3 left

💡 Hint

Common Mistakes

Using unquoted platform names in the condition.

Using wrong platform string like 'win32' for Linux.

Confusing marker name with platform string.

The platform string for Linux is 'linux' (with quotes). The marker name is linux_only to select the test.

5fill in blank

hard

Fill all three blanks to create a parametrized test with a marker and skip condition.

PyTest

import pytest

@pytest.mark.[1]
@pytest.mark.parametrize("input", [1, 2, 3])
@pytest.mark.skipif(input == [2], reason="Skip input 2")
def test_values(input):
    assert input != 0

# Run tests with pytest -m [3]

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

Aparam

B2

Attempts:

3 left

💡 Hint

Common Mistakes

Using different marker names in code and command.

Using wrong skip condition value.

Forgetting to quote marker names in code.

The marker name is param. The skip condition checks if input equals 2. The run command uses the same marker name param.

Practice

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

easy

A. To write tests faster by auto-generating code

B. To change the Python version used for tests

C. To automatically fix failing tests

D. To group tests so you can run specific sets easily

Solution

1. Step 1: Understand what markers do in pytest

   Markers are labels you add to tests to group or categorize them.

2. Step 2: Identify the main use of markers

   Markers help you run only certain groups of tests, saving time and focusing effort.

3. Final Answer:

   To group tests so you can run specific sets easily -> Option D

4. Quick Check:

   Markers group tests = B [OK]

Hint: Markers help run selected tests quickly [OK]

Common Mistakes:

• Thinking markers auto-fix tests
• Confusing markers with code generation
• Believing markers change Python version

2. Which of the following is the correct way to mark a test as 'slow' in pytest?

easy

A. @pytest.slow
def test_example(): pass

B. @pytest.mark.slow
def test_example(): pass

C. @slow_mark
def test_example(): pass

D. @mark.slow
def test_example(): pass

Solution

1. Step 1: Recall pytest marker syntax

   Markers are used with @pytest.mark.<marker_name> before the test function.

2. Step 2: Match the correct syntax

   Only '@pytest.mark.slow' is the correct way to mark a test as slow.

3. Final Answer:

   @pytest.mark.slow\ndef test_example(): pass -> Option B

4. Quick Check:

   Use @pytest.mark.marker_name = D [OK]

Hint: Use @pytest.mark.marker_name to mark tests [OK]

Common Mistakes:

• Omitting 'pytest' before 'mark'
• Using wrong decorator names
• Confusing marker syntax with other decorators

3. Given the code below, what tests will run when executing pytest -m "slow and not network"?

@pytest.mark.slow
def test_a(): pass

@pytest.mark.network
def test_b(): pass

@pytest.mark.slow
@pytest.mark.network
def test_c(): pass

def test_d(): pass

medium

A. test_b and test_c

B. test_a and test_c

C. Only test_a

D. test_a, test_b, test_c, and test_d

Solution

1. Step 1: Understand the marker expression

   The command runs tests marked 'slow' but NOT marked 'network'.

2. Step 2: Check each test's markers

   test_a is 'slow' only (runs), test_b is 'network' only (excluded), test_c is both 'slow' and 'network' (excluded), test_d has no markers (excluded).

3. Final Answer:

   Only test_a -> Option C

4. Quick Check:

   Run tests with slow and not network = C [OK]

Hint: Use 'and not' to exclude markers in pytest -m [OK]

Common Mistakes:

• Including tests with 'network' marker
• Running unmarked tests by default
• Misunderstanding boolean logic in marker expressions

4. What is wrong with this pytest marker usage?

@pytest.mark.skipif(sys.platform == 'win32')
def test_func():
    assert True

medium

A. Missing import of sys module

B. Incorrect marker name 'skipif'

C. Missing parentheses after skipif

D. Cannot use conditions in markers

Solution

1. Step 1: Check the code for required imports

   The code uses 'sys.platform' but does not import 'sys'.

2. Step 2: Verify marker syntax

   '@pytest.mark.skipif(condition)' is correct syntax, so no error there.

3. Final Answer:

   Missing import of sys module -> Option A

4. Quick Check:

   Use imports for conditions in markers [OK]

Hint: Always import modules used in marker conditions [OK]

Common Mistakes:

• Forgetting to import modules like sys
• Misnaming skipif marker
• Using skipif without condition parentheses

5. You want to run only tests marked as 'database' but skip those also marked 'slow'. Which pytest command achieves this?

hard

A. pytest -m "database and not slow"

B. pytest -m "slow and not database"

C. pytest -m "database or slow"

D. pytest -m "not database and slow"

Solution

1. Step 1: Understand the requirement

   Run tests with 'database' marker but exclude those with 'slow'.

2. Step 2: Translate to pytest marker expression

   Use 'database and not slow' to select tests marked database but not slow.

3. Final Answer:

   pytest -m "database and not slow" -> Option A

4. Quick Check:

   Use 'and not' to exclude markers [OK]

Hint: Combine markers with 'and not' to exclude tests [OK]

Common Mistakes:

• Swapping marker names in the expression
• Using 'or' instead of 'and not'
• Misunderstanding marker logic in pytest -m