Python Coding Challenge - Question with Answer (ID -080626)

 

Explanation:

🔹 Step 1: Create List

x = [4,3,2,1]

Current list:

[4,3,2,1]

🔹 Step 2: Create Special Iterator

it = iter(x.pop, 2)

This is the 2-argument version of iter():

iter(callable, sentinel)

Meaning:

Keep calling callable()

until it returns sentinel

Here:

callable = x.pop

sentinel = 2

So Python will repeatedly do:

x.pop()

until:

x.pop() == 2

🔹 Step 3: Convert Iterator to List

list(it)

Python starts calling:

x.pop()

again and again.

🔹 Step 4: First Call

x.pop()

removes:

1

List becomes:

[4,3,2]

Returned value:

1

Check:

1 == 2

❌ No

Store:

[1]

🔹 Step 5: Second Call

x.pop()

removes:

2

List becomes:

[4,3]

Returned value:

2

Check:

2 == 2

✅ Yes

This is the sentinel value.

Python immediately stops iteration.

⚠️ Sentinel value is not included in the result.

At this point the iterator ends.

So collected values are:

[1]

Final Output:

[1]