Python Coding challenge - Day 1022| What is the output of the following Python Code?

 

Code Explanation

1. Defining the Class

class Tool:

A class named Tool is defined.

2. Defining Method run

    def run(self):

        return "old"

A method named run is created.

If called normally:

Tool().run() → "old"

At this moment:

Tool.run → original method

3. Creating an Object

t = Tool()

An instance t of class Tool is created.

Important:

The object does NOT store the method inside itself.

It looks up methods dynamically from the class.

4. Modifying the Class at Runtime

Tool.run = lambda self: "new"

The class method run is replaced.

Now:

Tool.run → new lambda function

This change affects:

All future objects

All existing objects

Because method lookup happens at call time, not at object creation time.

5. Calling the Method

print(t.run())

Step-by-step:

Python looks for run in t.__dict__ → ❌ not found.

Looks in class Tool.

Finds the new lambda function.

Executes it.

Returns "new".

6. Final Output

new

✅ Final Answer

✔ Output:

new

400 Days Python Coding Challenges with Explanation