What are decorators in Python and how do they work with classes?

What are decorators in Python and how do they work with classes?

Decorators are functions that modify the behavior of another function or method. In Python, they are often used with classes to add functionality.

Can you give me an example of a class decorator?

Sure! Here's a simple class decorator that adds a greeting method to any class it decorates:

def add_greeting(cls):
    cls.greet = lambda self: 'Hello!'
    return cls

@add_greeting
class MyClass:
    pass

obj = MyClass()
print(obj.greet())  # Output: Hello!

What about method decorators? How do they differ?

Method decorators are similar but are applied to individual methods within a class. They can modify the method's behavior without affecting the entire class.

Can you show me a method decorator example?

Absolutely! Here's an example of a method decorator that logs the method call:

def log_method_call(method):
    def wrapper(self, *args, **kwargs):
        print(f'Calling method: {method.__name__}')
        return method(self, *args, **kwargs)
    return wrapper

class MyClass:
    @log_method_call
    def say_hello(self):
        return 'Hello!'

obj = MyClass()
obj.say_hello()  # Logs: Calling method: say_hello