The answer is the list comprehension `minors = [user['name'] for user in users if user['age'] < 18]` because it directly combines filtering and field extraction into a single, readable line. This approach is correct because list comprehensions are the idiomatic Python method for transforming an iterable while applying a conditional filter, replacing the verbose for-loop and if-statement pattern with a concise expression that reads like plain English: “take each user’s name for every user in users where the age is under 18.” On the Certified Entry-Level Python Programmer PCEP exam, this tests your understanding of sequence types and list comprehensions, a core competency in the “Data Aggregations” section. A common trap is forgetting that the filter condition comes after the loop, not before the `for` keyword, or trying to use a dictionary comprehension when you need a list of values. Memory tip: think of it as “what you want, for each item, if condition” — the order in the comprehension mirrors the English sentence structure.
PCEP Computer Programming and Python Fundamentals Practice Question
This PCEP practice question tests your understanding of computer programming and python fundamentals. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A junior developer is working on a script that processes user data. The script reads a CSV file into a list of dictionaries. Each dictionary represents a user with keys 'name', 'age', and 'email'. The developer needs to filter out users under 18 and store their names in a list. The current code is:
The code works, but the senior developer says it is not idiomatic and suggests a more concise solution. Which of the following approaches is the best replacement?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
minors = [user['name'] for user in users if user['age'] < 18]
Option D is correct because it uses a list comprehension to directly extract the 'name' field from each user dictionary where the age is under 18, making the code concise and Pythonic. The original code works but is verbose; list comprehensions are the idiomatic Python approach for transforming and filtering iterables in a single readable line.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
minors = []
for i in range(len(users)):
if users[i]['age'] < 18:
minors.append(users[i]['name'])
Why it's wrong here
Same as original but uses index, not idiomatic.
✗
minors = [user for user in users if user['age'] < 18]
minors = [user['name'] for user in users if user['age'] < 18]
Why this is correct
Concise and idiomatic list comprehension.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Python Institute often tests the distinction between filtering entire objects versus extracting specific fields, so candidates may pick Option B (which filters dictionaries) instead of Option D (which extracts the 'name' field), missing the requirement to store only names.
Detailed technical explanation
How to think about this question
List comprehensions in Python are syntactic sugar that compile to efficient bytecode, often faster than manual for-loop appending due to reduced attribute lookups and function calls. In real-world data pipelines, using list comprehensions over map/filter or index loops improves code maintainability and performance, especially when processing large CSV-derived datasets where readability and speed matter.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the PCEP exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Computer Programming and Python Fundamentals — This question tests Computer Programming and Python Fundamentals — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: minors = [user['name'] for user in users if user['age'] < 18] — Option D is correct because it uses a list comprehension to directly extract the 'name' field from each user dictionary where the age is under 18, making the code concise and Pythonic. The original code works but is verbose; list comprehensions are the idiomatic Python approach for transforming and filtering iterables in a single readable line.
What should I do if I get this PCEP question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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 →
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.
This PCEP 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 PCEP 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.