Decorators @ annotation

[buran]

How is that good if I want to use my function in other decorators?

You use the decorator on your function, not your function in decorators.
Actually the decorators are just a syntactic sugar to pass a function into other function

Also maybe have a look at Is a Python Decorator the same as Java annotation, or Java with Aspects?

Other useful SO question to understand decorators How do I make function decorators and chain them together?

Primer on Python Decorators