python when are decorators called code example

Example 1: decorator python

def our_decorator(func):
    def function_wrapper(x):
        print("Before calling " + func.__name__)
        func(x)
        print("After calling " + func.__name__)
    return function_wrapper

@our_decorator
def foo(x):
    print("Hi, foo has been called with " + str(x))

foo("Hi")

Example 2: python decorator

#Decorator are just function that take function as first
#parameter and return a function
def logging(f):
  def decorator_function(*args, **kwargs):
    print('executing '+f.__name__)
    return f(*args, **kwargs)
  return decorator_function
#Use it like this
@logging
def hello_world():
  print('Hello World')
#calling hello_world() prints out:
#executing hello_world
#Hello World