Test packages in PyTest - Test Execution Trace

Test Overview

This test package contains two simple test files. It verifies that pytest can discover and run tests across multiple files inside a package.

Test Code - pytest

PyTest

import pytest

# File: tests/test_math.py

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

def test_subtraction():
    assert 5 - 3 == 2

# File: tests/test_strings.py

def test_uppercase():
    assert 'hello'.upper() == 'HELLO'

def test_isdigit():
    assert '1234'.isdigit() == True

# To run tests, execute: pytest tests/

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test runner starts and looks for tests in the 'tests' package	Pytest scans the 'tests' directory and finds test_math.py and test_strings.py	-	PASS
2	Pytest loads test_math.py and runs test_addition	Running test_addition function	Assert 1 + 1 == 2	PASS
3	Pytest runs test_subtraction in test_math.py	Running test_subtraction function	Assert 5 - 3 == 2	PASS
4	Pytest loads test_strings.py and runs test_uppercase	Running test_uppercase function	Assert 'hello'.upper() == 'HELLO'	PASS
5	Pytest runs test_isdigit in test_strings.py	Running test_isdigit function	Assert '1234'.isdigit() == True	PASS
6	Pytest finishes running all tests and reports results	All 4 tests passed	-	PASS

Failure Scenario

Failing Condition: A test assertion fails, for example if test_addition asserts 1 + 1 == 3

Execution Trace Quiz - 3 Questions

What does pytest do first when running tests in a package?

A It compiles the test files into bytecode

B It runs all tests without scanning

C It scans the package directory to find test files

D It deletes old test results

Key Result

Organizing tests into packages with multiple files helps pytest discover and run tests efficiently, keeping tests modular and easy to maintain.