Human: Can you write me a Python decorator that retries a function on failure?
Assistant: Here's a retry decorator with configurable attempts and exponential backoff:

```python
import time
import functools

def retry(max_attempts=3, delay=1, backoff=2):
    def decorator(func):
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            attempts = 0
            current_delay = delay
            while attempts < max_attempts:
                try:
                    return func(*args, **kwargs)
                except Exception as e:
                    attempts += 1
                    if attempts == max_attempts:
                        raise
                    time.sleep(current_delay)
                    current_delay *= backoff
        return wrapper
    return decorator
```

Usage:
```python
@retry(max_attempts=3, delay=0.5)
def fetch_data(url):
    response = requests.get(url)
    response.raise_for_status()
    return response.json()
```

We decided to use exponential backoff by default. TODO: add logging to the retry attempts. TODO: add support for specifying which exception types to retry on. Should we also add a jitter factor to prevent thundering herd issues?