Minimal working decorator example in the style of `flask.App.route()`

decorators.py

import functools
import numpy as np


class DataServiceManager:
    def __init__(self) -> None:
        pass

    def service(self, **options):
        print('service() called')

        def decorator(func):
            print('decorator() called')

            @functools.wraps(func)
            def wrapper():
                print("Something is happening before the function is called.")
                result = func()
                print("Something is happening after the function is called.")
                return result
            return wrapper
        
        return decorator


svcmgr = DataServiceManager()


@svcmgr.service()
def getData() -> np.ndarray:
    """ Pointer to data """
    print('get_data() called')
    pass

getData()