Why organized tests scale with projects in PyTest - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a simple test function using pytest.

PyTest

def test_addition():
    assert 2 + 2 == [1]

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

A5

B3

C22

D4

Attempts:

3 left

💡 Hint

Common Mistakes

Using 5 or 3 instead of 4 will cause the test to fail.

Writing the number as a string like '4' instead of 4.

The test checks if 2 + 2 equals 4, which is true. This simple assertion helps verify basic functionality.

2fill in blank

medium

Complete the code to mark a test as expected to fail using pytest.

PyTest

import pytest

@pytest.mark.[1]()
def test_fail_example():
    assert False

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

Askip

Bxfail

Cparametrize

Dfixture

Attempts:

3 left

💡 Hint

Common Mistakes

Using @pytest.skip will skip the test instead of marking it as expected fail.

Using @pytest.fixture or @pytest.parametrize are unrelated to expected failure.

The decorator @pytest.mark.xfail() marks the test as expected to fail, so pytest reports it differently without failing the whole suite.

3fill in blank

hard

Fix the error in the test function to correctly check if a list is empty.

PyTest

def test_empty_list():
    my_list = []
    assert [1] == 0

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

Alen(my_list)

Bmy_list.length

Cmy_list[0]

Dmy_list

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to access my_list[0] causes an error if the list is empty.

Using my_list.length is invalid in Python.

Using len(my_list) returns the number of items in the list, which should be 0 if empty. Checking my_list directly won't compare to 0.

4fill in blank

hard

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

PyTest

def test_substring():
    text = "hello world"
    assert [1] in [2]

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

A"world"

B"hello"

Ctext

D"planet"

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the order of substring and string will cause the test to fail.

Using a substring not present in the string will fail the test.

The test checks if the substring "world" is inside the string variable text. This is a common way to verify content in strings.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that filters words longer than 3 characters.

PyTest

words = ["cat", "house", "dog", "elephant"]
lengths = { [1]: [2] for [3] in words if len([3]) > 3 }

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

Aword

Blen(word)

D{

Attempts:

3 left

💡 Hint

Common Mistakes

Not starting with a curly brace causes syntax errors.

Swapping key and value will produce incorrect dictionaries.

Using a variable name not defined in the loop causes errors.

The dictionary comprehension syntax starts with a curly brace {. It maps each word to its length len(word) for words longer than 3 characters.