Quick Answer
The answer is str. When b is zero, the ternary conditional expression a / b if b != 0 else 'undefined' evaluates the else branch, which explicitly returns the string literal 'undefined', so the variable result is assigned a value of type string. This demonstrates how the ternary conditional expression data type is determined by whichever branch executes—in this case, the else branch provides a str, not a numeric type. On the Certified Entry-Level Python Programmer PCEP exam, this tests your understanding that a conditional expression does not unify types; it simply returns the value from the chosen branch, making it a common trap to assume result would be a float or None. A helpful memory tip: the ternary operator is like a fork in the road—the data type of the result follows the path you actually take, not the one you intended.
This PCEP practice question tests your understanding of data types, variables, basic i/o and operators. 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 developer needs to store the result of dividing two numbers, a/b, but only if b is not zero. They write: result = a / b if b != 0 else 'undefined'. What is the data type of result when b is zero?
float
Why wrong: When b is 0, result is assigned 'undefined', which is a string.
NoneType
Why wrong: None is not returned; the string 'undefined' is returned.
bool
Why wrong: No boolean value is involved.
str
The else clause returns a string literal, so result is a string.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
str
When `b` is zero, the expression `a / b if b != 0 else 'undefined'` evaluates to the string literal `'undefined'`. Therefore, the variable `result` is assigned a value of type `str` (string). The conditional expression explicitly returns a string in the else branch, making option D correct.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
float
Why it's wrong here
When b is 0, result is assigned 'undefined', which is a string.
NoneType
Why it's wrong here
None is not returned; the string 'undefined' is returned.
bool
Why it's wrong here
No boolean value is involved.
str
Why this is correct
The else clause returns a string literal, so result is a string.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Python Institute often tests the ternary conditional expression to see if candidates mistakenly think the else branch returns a special 'undefined' value (like in JavaScript) instead of recognizing it as a plain Python string literal.
Detailed technical explanation
This question tests the ternary conditional expression syntax in Python: `value_if_true if condition else value_if_false`. The entire expression is evaluated as a single value, and its type is determined by the branch taken. In real-world code, returning a string like `'undefined'` can cause type inconsistency downstream; a more robust approach might raise an exception or return `None` to signal an error, preserving type safety.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
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
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Data Types, Variables, Basic I/O and Operators — study guide chapter
Learn the concepts, then practise the questions
Data Types, Variables, Basic I/O and Operators practice questions
Targeted practice on this topic area only
All PCEP questions
510 questions across all exam domains
Certified Entry-Level Python Programmer PCEP study guide
Full concept coverage aligned to exam objectives
PCEP practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise PCEP questions linked to Computer Programming and Python Fundamentals.
Practise PCEP questions linked to Data Types, Variables, Basic I/O and Operators.
Practise PCEP questions linked to Control Flow, Loops, Lists and Logic.
Practise PCEP questions linked to Functions, Tuples, Dictionaries and Exceptions.
Practise PCEP questions linked to PCEP fundamentals.
Practise PCEP questions linked to PCEP scenario.
Practise PCEP questions linked to PCEP troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Data Types, Variables, Basic I/O and Operators — This question tests Data Types, Variables, Basic I/O and Operators — Read the scenario before looking for a memorised answer..
The correct answer is: str — When `b` is zero, the expression `a / b if b != 0 else 'undefined'` evaluates to the string literal `'undefined'`. Therefore, the variable `result` is assigned a value of type `str` (string). The conditional expression explicitly returns a string in the else branch, making option D correct.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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 →
Last reviewed: Jun 30, 2026
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.