Is a Python Decorator the same as Java annotation, or Java with Aspects?

Question

Are Python Decorators the same or similar, or fundamentally different to Java annotations or something like Spring AOP, or Aspect J?

Answer 1

Python decorators are just syntactic sugar for passing a function to another function and replacing the first function with the result:

@decorator
def function():
    pass

is syntactic sugar for

def function():
    pass
function = decorator(function)

Java annotations by themselves just store metadata, you must have something that inspects them to add behaviour.

 

Java AOP systems are huge things built on top of Java, decorators are just language syntax with little to no semantics attached, you can't really compare them.