PCEP variable shadowing Practice Question

Exhibit

Python 3.11.0 (default, Oct 24 2022, 14:48:10)
[GCC 11.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> x = [1, 2, 3]
>>> for i in range(len(x)):
...     x.insert(i, x.pop())
...
>>> x
[1, 2, 3]

Refer to the exhibit. What is the final value of x after executing the code?

⚠ Common exam trap

The trap is that students think the list remains unchanged, but if the loop variable is named the same as the list, the list variable is overwritten during iteration.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

[1, 2, 3]

The code uses `x` as both the list variable and the loop variable. During iteration, `x` is reassigned to each element. After the loop, `x` holds the last element, which is `3`. Since `3` is not among the options, none of the given options is correct.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✗
[1, 1, 1]
Why it's wrong here
Incorrect because after the loop, x is 3, not [1, 1, 1].
✗
[3, 2, 1]
Why it's wrong here
Incorrect because after the loop, x is 3, not [3, 2, 1].
✓
[1, 2, 3]
Why this is correct
Incorrect because the list is not preserved; x is reassigned to the last element (3).
✗
[3, 1, 2]
Why it's wrong here
Incorrect because after the loop, x is 3, not [3, 1, 2].

Go deeper

PCEP variable shadowing Practice Question

Exhibit

Why each option matters

Option-by-option breakdown

Related to this question