Called a decorator's returned value — Python

November 25, 2021

I came across a problem for python decorator.

The question is:
Create a decorator which is responsible for multiplication of 2 numbers (say a,b), this multiplication of the numbers gives another number(say c).

Then needed to a create a actual function which does the summation of a,b and c.
Something like:

Decorator : a*b => c

Actual function: a+b+c

I have reached until this stage:

def my_decorator(func):
    def addition(a,b):
        c = a*b
        return c
    return addition

@my_decorator
def actual_func(a,b):
    return a+b+c

But it gives error all the time.

>Solution :

Actual func

Takes a, b and multiplies them
decorator sums original numbers plus ouput of multiply func

Code

def my_decorator(func):
    def addition(a,b):
        c = func(a, b)               # use multiplication function
        return a + b + c             # performs desired calculation
    return addition                  # modified function for desired calculation

@my_decorator
def actual_func(a,b):
    return a*b      # does multiplication

actual_func(2, 4)   # return 14 i.e. 2 + 4 + 2*4