Python Coding challenge - Day 922| What is the output of the following Python Code?

 

Code Explanation:

1. Defining a Class

class Loop:

A new class named Loop is defined.

This class will be made iterable, meaning it can be used inside a for loop.

2. Defining the __iter__ Method

    def __iter__(self):

        return iter([10,20])

What this does:

__iter__ is a special method that Python uses when an object should act like a sequence or iterable.

When Python encounters for i in Loop():, it calls __iter__() on that object.

Inside this method:

iter([10,20]) creates an iterator over a list containing two elements: 10 and 20.

Returning this iterator allows Python to loop over those numbers one by one.

So:

The object itself does not store the numbers —

it simply returns an iterator that yields 10 and 20.

3. Using the Class in a for Loop

for i in Loop():

Here is what happens step-by-step:

Python creates a temporary Loop() object.

Python calls that object’s __iter__() method.

That returns an iterator based on [10, 20].

The loop receives numbers in order:

First 10

Then 20

4. Printing Each Value

    print(i, end="-")

Each value retrieved from iteration is printed.

end="-" ensures:

A dash - is printed instead of a newline

So values appear on one line separated by -

Thus printing proceeds:

For first value 10 → prints 10-

For second value 20 → prints 20-

They are printed consecutively on one line.

5. Final Output

10-20-

There is an extra dash at the end because of the final end="-".

Final Answer

10-20-

500 Days Python Coding Challenges with Explanation