Pytest's Built-in Fixtures tmp_path and monkeypatch Simplify Test Setup

Pytest includes several built-in fixtures that reduce boilerplate and improve test reliability. The tmp_path fixture automatically provides a unique temporary directory path for each test, while monkeypatch offers a versatile toolkit for modifying objects, environment variables, and system paths during testing. A key advantage of monkeypatch over direct environment manipulation via os.environ is that all changes are automatically reverted once the test completes, preventing state from leaking into subsequent tests. In contrast, using os.environ directly can cause unintended side effects, as modifications persist across the entire test session. The full list of pytest built-in fixtures is available in the official pytest documentation.