Python Coding challenge - Day 686| What is the output of the following Python Code?

 

Code Explanation:

1. Defining the decorator function

def dec(f):

Here, dec is a decorator function that takes another function f as its argument.

A decorator is a function that modifies the behavior of another function.

2. Defining the wrapper function inside dec

    def wrap(x):

        print("Wrapped!")

        return f(x)

Inside dec, we define another function wrap.

wrap takes one argument x.

It first prints "Wrapped!".

Then it calls the original function f(x) and returns its result.

So this wrap function adds extra behavior (printing) before calling the actual function.

3. Returning the wrapper

    return wrap

Instead of returning the original function, dec returns the modified wrap function.

This means: when dec is used, the original function is replaced by wrap.

4. Decorating function g

@dec

def g(x): return x**2

@dec is shorthand for:

g = dec(g)

So the function g(x) (which normally just does x**2) is wrapped by the decorator.

Now, calling g(x) really means calling wrap(x).

5. Calling g(4)

print(g(4))

Since g was decorated, g(4) calls wrap(4).

Step by step:

"Wrapped!" is printed.

Then the original g(4) → 4**2 = 16 is computed.

That result (16) is returned to print.

Final Output

Wrapped!

16

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