Can the decorator pattern be applied to classes in Python, and how to implement it?

Yes, in Python, the decorator pattern can be applied to classes. A class decorator is a class that takes another class or object and extends or modifies its behavior without changing the original code.

Example of implementing a class decorator:

class Decorator:
    def __init__(self, wrapped):
        self._wrapped = wrapped

    def __getattr__(self, name):
        # Delegate attribute calls to the wrapped object
        return getattr(self._wrapped, name)

    def new_method(self):
        return "Additional behavior"


class Original:
    def original_method(self):
        return "Original behavior"


obj = Original()
decorated_obj = Decorator(obj)

print(decorated_obj.original_method())  # Original behavior
print(decorated_obj.new_method())       # Additional behavior

Thus, the class decorator wraps an object and can add new methods or modify existing ones, while preserving the interface of the original object.