Decorators in python

Decorators: 

Before knowing about the decorators we should have basic knowledge about the functions.

Python’s functions are first-class objects. You can assign them to variables, store them in data structures, pass them as arguments to other functions, and even return them as values from other functions.

A decorator is a function that receives another function as argument. The behaviour of the argument function is extended by the decorator without actually modifying it.

def calculate_decorator(function_parameter): #receives another function as argument

    def warp_calculation(cal_num): # wrap the function and extends its behaviour

        add = function_parameter(cal_num) + 4
        print(add)

    return warp_calculation  # return wrapped function

def calculation(number):

    return number # return number

calculation  = calculate_decorator(calculation)
calculation(3)

Output:

    

(or another way as follow)

@[decorator_function_name] syntax to specify a decorator function

def calculate_decorator(function_parameter): #receives another function as argument

    def warp_calculation(cal_num): # wrap the function and extends its behaviour

        add = function_parameter(cal_num) + 4
        print(add)

    return warp_calculation # return wrapped function

@calculate_decorator
def calculation(number):

    return number # return number

calculation(3)

Output