What are decorators in Python and how do they work?

What are decorators in Python and how do they work?

Decorators are a way to modify or enhance functions or methods in Python. They allow you to wrap another function to extend its behavior without permanently modifying it.

Can you give me an example of a simple decorator?

Sure! Here's a simple decorator that prints 'Hello' before calling the function:

def hello_decorator(func):
    def wrapper():
        print('Hello')
        func()
    return wrapper

@hello_decorator
def greet():
    print('Welcome!')

# Calling greet() will print 'Hello' followed by 'Welcome!'
greet()

What are some common use cases for decorators?

Common use cases include logging, enforcing access control, caching results, and measuring execution time of functions.

How do I pass arguments to a decorator?

To pass arguments to a decorator, you need to create a decorator factory. Here's an example:

def repeat(num_times):
    def decorator_repeat(func):
        def wrapper(*args, **kwargs):
            for _ in range(num_times):
                func(*args, **kwargs)
        return wrapper
    return decorator_repeat

@repeat(3)
def say_hello():
    print('Hello!')

# Calling say_hello() will print 'Hello!' three times.
say_hello()