Question about return statement in decorator function

Question

Hello world! I've solved "Decorators" exercise where you need to code to make the text uppercase, but when I compared my code with Sololearn solution, there was only one difference at line #4 where I used "return text.upper()" instead of "return func(text).upper()" as suggested by SL solution. Anyway, the code passed tests, but I still wonder if the correct way was SL solution and why. Greatly appreciate for any help.

text = input()
def uppercase_decorator(func):
····def wrapper(text):
········return text.upper() # <-- HERE
····return wrapper

@uppercase_decorator
def display_text(text):
····return(text)
print(display_text(text))

Answer 1

The point of a decorator is to combine two functions, adding some extra behavior to an existing function.

The concept is similar to function composition (function chaining), but implemented differently.

With a function chain, you run the first function f on the input data, then take the result and run it on the second function.
So it looks like: g(f(x))

But the decorator pattern changes the behavior of the original function itself. The decorator takes in another function, and returns a different function, but lets the input data flow through the whole thing.
So we might express it like: g(f)(x)

In your implementation you ignored this pattern and totally circumvented the inner function, so you only implemented a decorator shell that doesn't execute the decorated function, just returns the effect on the original argument. Coincidently, the display_text in the sample task doesn't do anything to its argument... so the result is not noticable.
What you did is like: g(x)

You are meant to execute func inside the wrapper, that's how both function behaviors can be realized.

Answer 2

I also solved this task.

If we get direct access to the "text" argument, then it is silly to call an additional function.

P. S: "And in general, I believe that it is not in vain that the SoloLearn hides test data from everyone, it allows users to show their individuality."

Answer 3

Tibor Santa , I completely agree with you, this is another omission of SoloLearn.

I once wrote code that more clearly demonstrates the capabilities of the decorator:
https://code.sololearn.com/cpAJapSWADmf/?ref=app