PyTest Fixtures & Scope Management (session, module, function)

1Concept

Fixtures (`@pytest.fixture`) provide reusable test setup and teardown. The `scope` parameter controls lifecycle: `function` (default, fresh per test), `class`, `module` (once per file), or `session` (once per entire test run).

2Architecture Diagram

@pytest.fixture(scope="session") ---> DB container initialized ONCE for all tests
@pytest.fixture(scope="function") ---> Table cleaned before every individual test

3Code Example

fixture_sample = '''
import pytest

@pytest.fixture(scope="module")
def database_client():
    client = {"connected": True}
    yield client # Setup
    client["connected"] = False # Teardown after all module tests complete

def test_query(database_client):
    assert database_client["connected"] is True
'''
print("=== PyTest Fixture Lifecycle ===")
print(fixture_sample.strip())

4Expected Output

=== PyTest Fixture Lifecycle ===
import pytest

@pytest.fixture(scope="module")
def database_client():
    client = {"connected": True}
    yield client # Setup
    client["connected"] = False # Teardown after all module tests complete

def test_query(database_client):
    assert database_client["connected"] is True

5Key Takeaways

• ✓Code before `yield` is setup; code after `yield` is teardown.
• ✓`autouse=True` executes fixtures automatically without explicit argument passing.
• ✓`conftest.py` defines fixtures shared across all test files in a directory.