What is the `logging` module best practices?

Question

Accepted Answer

**Logging** — configurable event recording for debugging and monitoring.

```python
import logging

# Best practice: use module-level logger
logger = logging.getLogger(__name__)

def process_data(data):
    logger.info("Processing %d items", len(data))
    try:
        result = transform(data)
        logger.debug("Transform complete: %s", result)
        return result
    except Exception:
        logger.exception("Failed to process data")
        raise

# Configuration
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
    handlers=[
        logging.StreamHandler(),
        logging.FileHandler("app.log"),
    ]
)

# Library logging: set WARNING to avoid noise
logging.getLogger("requests").setLevel(logging.WARNING)
```

**Rules:**
- Use `logging.getLogger(__name__)` not `logging.info()`.
- Use `%s` formatting not f-strings.
- Use `logger.exception()` for full tracebacks.

Python: What is the `logging` module best practices?