Decorators extend functions, methods, classes without explicitly modifying the code of the item being decorated.

example of a decorator Italic (skelleton structure only):

def decorator_function(func):
    ''' Receives the function being decorated as first argument'''
 
    def actual_decorator(*args, **kwargs): 
        '''function that actually performs the decorated logic '''
 
        # do something, before original logic
 
        #call the original function        
        func(*args,**kwargs)
 
        # and/or do something after. 
 
        #return result 
 
    #return the actual decorator so it gets called by calling context . 
    return actual_decorator

example of decorator with argumentsItalic (skelleton structure only):

def decorator_function(a, b):
    ''' Receives the decorator arguments'''
 
    def additional_wrapper(func):
        ''' receivs the function (and its arguments) being decorated '''
 
        def actual_decorator(*args, **kwargs): 
            '''function that actually performs the decorated logic '''
 
            #arguments a and b passed from outer fuction are in scope but read only. 
               if a > b:
                   pass         
            # do something, before original logic                      
 
            #call the original function            
            func(*args,**kwargs)
 
            # and/or do something after. 
 
            #return result
 
        # return function to calling context (so that it gets executed).    
        return actual_decorator   
 
    #return fuction to calling context (so that it gets executed).
    return additional_wrapper

Related:

• PEP 318 – Decorators for Functions and Methods
• Learning Python Decorators by Example (pybit.es)
• PythonDecorators (wiki.python.org)
• Using Python Class Decorators (builtin.com)
• Python Metaclasses (realpython.com)¹⁾
• Primer on Python decorators (realpython.com)
• article on property decorator