Grouping related tests in PyTest

Introduction

Grouping related tests helps keep your tests organized and easy to find. It makes running and understanding tests simpler.

When you have many tests for different parts of your app and want to keep them separate.

When you want to run only a specific set of tests related to one feature.

When you want to share setup or cleanup code for a group of tests.

When you want to improve test reports by grouping results logically.

Syntax

PyTest

import pytest

@pytest.mark.group_name
def test_example():
    assert True

# Or use classes to group tests
class TestGroupName:
    def test_one(self):
        assert True
    def test_two(self):
        assert True

You can use @pytest.mark to tag tests with a group name.

Using classes groups tests inside one container without needing extra decorators.

Examples

Here, both tests are marked with 'login' to group them.

PyTest

import pytest

@pytest.mark.login
def test_login_success():
    assert True

@pytest.mark.login
def test_login_failure():
    assert False

Tests inside the class TestMathOperations are grouped together.

PyTest

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

    def test_subtract(self):
        assert 2 - 1 == 1

Sample Program

This example shows two ways to group tests: using @pytest.mark and using classes.

Tests marked with 'calculator' belong to one group, and string tests are grouped in a class.

PyTest

import pytest

@pytest.mark.calculator
def test_multiply():
    assert 3 * 3 == 9

@pytest.mark.calculator
def test_divide():
    assert 10 / 2 == 5

class TestStringMethods:
    def test_upper(self):
        assert 'hello'.upper() == 'HELLO'

    def test_isupper(self):
        assert 'HELLO'.isupper() is True

Important Notes

Use descriptive group names to make tests easy to find.

You can run tests by group using pytest -m group_name.

Classes group tests logically and can share setup code with setup_method.

Summary

Grouping tests keeps your test suite organized and easier to manage.

Use @pytest.mark or classes to group related tests.

Running tests by group helps focus on specific features or fixes.