A typical implementation of a decorator used as @retry(times=3) needs how many nested callables?

Options

1. 1
2. 2
3. 3 (Correct option)
4. 4

Answer

3

Why

@retry(times=3) first CALLS retry(3). That call must return a decorator.

The decorator receives your function and returns a wrapper.

The wrapper runs every time your function is called.

So there are three levels: retry (settings) → decorator (function) → wrapper (call arguments).

def retry(times):
    def decorator(func):
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            for attempt in range(times):
                try:
                    return func(*args, **kwargs)
                except Exception:
                    if attempt == times - 1:
                        raise
        return wrapper
    return decorator

Remember

A decorator with arguments is a function that returns a decorator.

Key terms

• Decorator
• Closure
• Higher-order function