PCEP Practice Question: Functions, Tuples, Dictionaries and Exceptions

Which of the following will raise a TypeError?

⚠ Common exam trap

Python Institute often tests the distinction between mutable and immutable types, specifically that tuples cannot be modified after creation, while lists, sets, and dictionaries can be changed via their respective methods or assignments.

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

✓

t = (1, 2); t[0] = 3

Tuples are immutable in Python; attempting to assign a value to an element using indexing (e.g., `t[0] = 3`) raises a `TypeError` with the message 'tuple' object does not support item assignment. This is a fundamental property of the tuple data type, designed to create fixed sequences that cannot be changed after creation.

Answer analysis

Option-by-option breakdown

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

✓
t = (1, 2); t[0] = 3
Why this is correct
Tuples are immutable; assignment to element raises TypeError.
✗
lst = [1, 2]; lst.extend([3, 4])
Why it's wrong here
List extend method works fine.
✗
x = {1, 2} & {2, 3}
Why it's wrong here
Set intersection works fine, returns {2}.
✗
d = {'a': 1}; d['b'] = 2
Why it's wrong here
Adding a new key to dictionary is allowed.

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PCEP Practice Question: Functions, Tuples, Dictionaries and Exceptions

Why each option matters

Option-by-option breakdown

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