Python Coding Challenge - Question with Answer (ID -080126)

 

Step-by-Step Explanation

1️⃣ Create the original list

arr = [1, 2, 3]

arr points to a list in memory:

arr → [1, 2, 3]

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2️⃣ Make a copy of the list

arr3 = arr.copy()

• .copy() creates a new list object with the same values.

• arr3 is a separate list, not a reference to arr.

arr → [1, 2, 3]
arr3 → [1, 2, 3] (different memory location)

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3️⃣ Modify the copied list

arr3.append(4)

This only changes arr3:

arr → [1, 2, 3]
arr3 → [1, 2, 3, 4]

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4️⃣ Print original list

print(arr)

✅ Output

[1, 2, 3]

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Key Concept

Operation	Effect
.copy()	Creates a new list
=	Only creates a reference
append()	Modifies list in place

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 Compare with reference assignment:

arr = [1, 2, 3]
arr3 = arr # reference, not copy
arr3.append(4)
print(arr)

Output:

[1, 2, 3, 4]

Because both variables point to the same list.

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Final Answer

👉 arr remains unchanged because arr3 is a separate copy, not a reference.

Printed Output:

[1, 2, 3]

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