Python Coding Challenge - Question with Answer (ID 200926)

 

Explanation:

1. Creating the List

x = [1]

A list containing 1 is created.

x refers to this list.

x → [1]

2. Assigning y = x

y = x

This does not create a new list.

Both variables point to the same list:

x ──┐

    ↓

  [1]

    ↑

y ──┘

So:

x is y

would already be True.

3. Using +=

x += [2]

For a list, += modifies the existing list in place.

The list changes from:

[1]

to:

[1, 2]

Because x and y refer to the same list, y also sees the change:

x ──┐

    ↓

 [1, 2]

    ↑

y ──┘

4. Checking Identity

print(x is y)

The is operator checks whether two variables refer to the same object.

Here:

x → same list ← y

Therefore:

x is y → True

⚡ Complete Flow

x = [1]

   ↓

y = x

   ↓

Both refer to the same list

   ↓

x += [2]

   ↓

Same list becomes [1, 2]

   ↓

x is y

   ↓

True

✅ Final Output:

True

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