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Decorators in Python 2026 – Best Practices for Writing Functions

Decorators are one of Python’s most powerful and elegant features. A decorator is a function that takes another function as input, adds some behavior to it, and returns a new function. In 2026, decorators are widely used for logging, authentication, caching, timing, validation, and more.

TL;DR — Key Takeaways 2026

A decorator is a function that wraps another function to extend its behavior
Use the @decorator_name syntax for clean application
Always use functools.wraps to preserve original function metadata
Decorators can accept parameters (decorator factories)

1. Basic Decorator


from functools import wraps

def timer(func):
    """Decorator that measures execution time."""
    @wraps(func)
    def wrapper(*args, **kwargs):
        import time
        start = time.perf_counter()
        result = func(*args, **kwargs)
        end = time.perf_counter()
        print(f"{func.__name__} took {end - start:.4f} seconds")
        return result
    return wrapper

@timer
def slow_operation(n: int):
    """Simulate a slow task."""
    import time
    time.sleep(0.1)
    return n * n

slow_operation(10)

2. Decorator with Parameters (Decorator Factory)


def repeat(times: int):
    """Decorator factory that repeats a function multiple times."""
    def decorator(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            for _ in range(times):
                result = func(*args, **kwargs)
            return result
        return wrapper
    return decorator

@repeat(3)
def greet(name: str):
    print(f"Hello, {name}!")

greet("Alice")

3. Best Practices for Decorators in 2026

Always use @wraps(func) from functools to preserve __name__, __doc__, and signature
Keep decorators simple and focused on a single responsibility
Use decorator factories when you need to pass parameters
Document what the decorator does and any side effects
Consider using libraries like wrapt for advanced decorator needs

Conclusion

Decorators are a cornerstone of modern Python development. In 2026, mastering decorators allows you to write clean, reusable, and powerful code by separating cross-cutting concerns from your core business logic. From simple timing and logging to complex authentication and caching, decorators remain one of Python’s most beloved features.

Next steps:

Review your codebase and identify repeated behavior that can be replaced with decorators
Related articles: Writing Functions in Python 2026 • Functions as Objects in Python 2026 • Defining a Function Inside Another Function in Python 2026

TL;DR — Key Takeaways 2026

1. Basic Decorator

2. Decorator with Parameters (Decorator Factory)

3. Best Practices for Decorators in 2026

Conclusion

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