main.py

class Logging: 
  
    def __init__(self, function): 
        self.function = function 
  
    def __call__(self, *args, **kwargs):
      print(f'Before {self.function.__name__}')
      self.function(*args, **kwargs)
      print(f'After {self.function.__name__}')
  
  
@Logging
def sum(x, y):
  print(x + y)

sum(5, 2)
> Before sum
> 7
> After sum

you forget to pass argument in line 16 😄

Thank you!