Question 384 of 169
PCAP Object-Oriented Programming Practice Question
Which of these is NOT a characteristic of Python's descriptor protocol?
⚠ Common exam trap
Python Institute often tests the misconception that descriptors are only for read-only attributes, but the trap here is that descriptors can be read-write (data descriptors) or read-only (non-data descriptors), and the protocol requires at least `__get__`, not that attributes are immutable.
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
✓
Descriptors are only used for attributes that are read-only
Descriptors are not limited to read-only attributes; they can control get, set, and delete operations. A descriptor that only implements `__get__` is a non-data descriptor, which can be overridden by instance attributes, while a data descriptor implements both `__get__` and `__set__` (and optionally `__delete__`), allowing full read-write control. The statement that descriptors are only for read-only attributes is false, as they are commonly used for computed properties, validation, and lazy evaluation.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
A descriptor can be used to create properties with custom behavior
Why it's wrong here
That is correct.
- ✓
Descriptors are only used for attributes that are read-only
Why this is correct
Descriptors can also handle writes and deletes.
- ✗
Class variables assigned to a descriptor are automatically intercepted
Why it's wrong here
Correct: descriptor protocol is triggered on instance attribute access.
- ✗
A descriptor must implement __get__
Why it's wrong here
At least __get__ is needed for a non-data descriptor.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 30, 2026
This PCAP practice question is part of Courseiva's free Python Institute certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PCAP exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.