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.
Which of the following is a valid Python variable name?
2var
Why wrong: Variable names cannot start with a digit.
_var
Underscores are allowed and commonly used.
my-var
Why wrong: Hyphens are not allowed in variable names; use underscores instead.
var$name
Why wrong: Special characters like $ are not allowed.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
_var
Option B (_var) is correct because Python variable names must start with a letter or an underscore, and can contain letters, digits, or underscores. The underscore is a valid starting character, making _var a legal identifier.
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.
2var
Why it's wrong here
Variable names cannot start with a digit.
_var
Why this is correct
Underscores are allowed and commonly used.
Related concept
Read the scenario before looking for a memorised answer.
my-var
Why it's wrong here
Hyphens are not allowed in variable names; use underscores instead.
var$name
Why it's wrong here
Special characters like $ are not allowed.
Common exam traps
Python Institute often tests the misconception that hyphens or special characters like '$' are allowed in variable names, or that digits can start a name, because candidates confuse Python's rules with those of other languages like JavaScript or PHP.
Detailed technical explanation
Python's identifier rules are defined in PEP 3131, which allows Unicode characters (e.g., letters from other scripts) but restricts the first character to a letter or underscore. Under the hood, the Python parser uses the `isidentifier()` method to validate names; for example, 'my-var' would be parsed as subtraction, not a variable. In real-world code, using underscores for private or internal variables (e.g., `_internal`) is a common convention, but hyphens cause syntax errors in assignments.
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: _var — Option B (_var) is correct because Python variable names must start with a letter or an underscore, and can contain letters, digits, or underscores. The underscore is a valid starting character, making _var a legal identifier.
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.