Python Testing

# Python Testing

> This skill provides comprehensive Python testing patterns using pytest as the primary testing framework.

## Testing Framework

Use **pytest** as the testing framework for its powerful features and clean syntax.

### Basic Test Structure

```python
def test_user_creation():
    """Test that a user can be created with valid data"""
    user = User(name="Alice", email="alice@example.com")

    assert user.name == "Alice"
    assert user.email == "alice@example.com"
    assert user.is_active is True
```

### Test Discovery

pytest automatically discovers tests following these conventions:
- Files: `test_*.py` or `*_test.py`
- Functions: `test_*`
- Classes: `Test*` (without `__init__`)
- Methods: `test_*`

## Fixtures

Fixtures provide reusable test setup and teardown:

```python
import pytest
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker

@pytest.fixture
def db_session():
    """Provide a database session for tests"""
    engine = create_engine("sqlite:///:memory:")
    Session = sessionmaker(bind=engine)
    session = Session()

    # Setup
    Base.metadata.create_all(engine)

    yield session

    # Teardown
    session.close()

def test_user_repository(db_session):
    """Test using the db_session fixture"""
    repo = UserRepository(db_session)
    user = repo.create(name="Alice", email="alice@example.com")

    assert user.id is not None
```

### Fixture Scopes