Fixture teardown (yield) in PyTest

Introduction

We use fixture teardown to clean up after a test runs. This keeps tests independent and avoids leftover data or settings.

When you open a file in a test and need to close it afterward.

When you connect to a database and want to disconnect after the test.

When you create temporary data or settings that should be removed after testing.

When you start a server or service for a test and need to stop it afterward.

Syntax

PyTest

import pytest

@pytest.fixture
def resource():
    # setup code
    setup_value = 'resource ready'
    yield setup_value
    # teardown code
    print('Cleaning up resource')

The code before yield runs before the test (setup).

The code after yield runs after the test (teardown).

Examples

This fixture prints 'Setup' before the test and 'Teardown' after the test.

PyTest

import pytest

@pytest.fixture
def sample_fixture():
    print('Setup')
    yield 'data'
    print('Teardown')

This fixture opens a file before the test and closes it after the test.

PyTest

import pytest

@pytest.fixture
def open_file():
    f = open('test.txt', 'w')
    yield f
    f.close()

Sample Program

This test uses a fixture that sets up a resource, yields it to the test, and then tears it down after the test finishes.

PyTest

import pytest

@pytest.fixture
def resource():
    print('Setup resource')
    yield 'resource ready'
    print('Teardown resource')

def test_example(resource):
    print(f'Test uses {resource}')
    assert resource == 'resource ready'

Important Notes

Always put the cleanup code after yield to ensure it runs after the test.

Teardown code runs even if the test fails or raises an error.

Using yield in fixtures helps keep setup and teardown code together for clarity.

Summary

Fixture teardown with yield runs cleanup code after a test finishes.

Setup code goes before yield, teardown code goes after.

This keeps tests clean and independent by removing temporary resources.