Python Coding challenge - Day 1139| What is the output of the following Python Code?

 

Code Explanataion:

🧩 1. Decorator Function Definition

def decorator(func):

Defines a function named decorator.

It takes another function (func) as an argument.

This is the core idea of decorators: functions that modify other functions.

🔁 2. Wrapper Function Inside Decorator

    def wrapper():

A nested function wrapper is defined.

This function will replace/extend the behavior of func.

✖️ 3. Modify Original Function Output

        return func() * 2

Calls the original function func().

Multiplies its result by 2.

Returns the modified value.

🔙 4. Return Wrapper Function

    return wrapper

The decorator returns the wrapper function.

This means the original function will be replaced by wrapper.

🎯 5. Applying the Decorator

@decorator

This is syntactic sugar for:

say = decorator(say)

It passes say into decorator and replaces it with wrapper.

📦 6. Original Function Definition

def say():

    return 5

A simple function that returns 5.

But due to the decorator, this function will not run directly.

🔄 7. What Actually Happens Internally

After decoration:

say = decorator(say)

Now say actually refers to wrapper.

When you call say(), it calls wrapper().

🖨️ 8. Function Call and Output

print(say())

Execution Flow:

say() → actually calls wrapper()

wrapper() → calls original func() → returns 5

5 * 2 = 10

✅ Final Output

10

Book:  700 Days Python Coding Challenges with Explanation