PCEP Practice Question: Data Types, Variables, Basic I/O and Operators
This PCEP practice question tests your understanding of data types, variables, basic i/o and operators. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 system administrator writes a script to monitor disk usage. The script reads a percentage from a file as a string, e.g., "100". The code:
usage = open("usage.txt").read().strip()
if usage > 80:
print("Warning: disk usage high")
else:
print("Disk usage OK")
Even when usage.txt contains "100", the script prints "Disk usage OK". The admin expected "Warning". What is the problem and how to fix?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The file reading returns a string; convert usage to int before comparison.
Option C is correct because the `read()` method returns the file content as a string. In Python, comparing a string to an integer with `>` performs lexicographic (character-by-character) comparison, not numeric comparison. For example, `"100" > 80` evaluates to `False` because `"1"` (ASCII 49) is less than `80` (integer), so the condition fails and the script prints "Disk usage OK". Converting the string to an integer with `int(usage)` before the comparison ensures numeric comparison works as intended.
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.
✗
The comparison operator > is incorrect; use >= instead.
Why it's wrong here
Using >= would still exhibit the same problem.
✗
The file is not properly closed; use with statement.
Why it's wrong here
The file is automatically closed after read, but not the core issue.
✓
The file reading returns a string; convert usage to int before comparison.
Why this is correct
String comparison can yield unexpected results; convert to int.
Related concept
Read the scenario before looking for a memorised answer.
✗
The strip() method removes newlines but not spaces; usage may have extra spaces.
Why it's wrong here
strip() removes leading/trailing whitespace, but the core issue is string comparison.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Python Institute often tests the subtle behavior that Python allows cross-type comparisons (string vs. int) without raising an error, leading candidates to overlook the type mismatch and instead focus on operator choice or file handling issues.
Detailed technical explanation
How to think about this question
Python’s comparison operators between different numeric types (e.g., int and float) work as expected, but comparing a string to an int triggers a `TypeError` in Python 3? Actually, Python 3 allows comparison between strings and integers without raising an error, but it uses a fixed ordering where all numeric types are considered less than all string types (since Python 3.0, comparisons between incompatible types return a consistent but arbitrary result). This means `"100" > 80` always evaluates to `False` because strings are always greater than numbers in Python’s type ordering, a behavior defined in CPython’s implementation of object comparison. In real-world monitoring scripts, failing to convert user input or file data to the correct type is a common source of silent logic bugs.
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.
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..
What is the correct answer to this question?
The correct answer is: The file reading returns a string; convert usage to int before comparison. — Option C is correct because the `read()` method returns the file content as a string. In Python, comparing a string to an integer with `>` performs lexicographic (character-by-character) comparison, not numeric comparison. For example, `"100" > 80` evaluates to `False` because `"1"` (ASCII 49) is less than `80` (integer), so the condition fails and the script prints "Disk usage OK". Converting the string to an integer with `int(usage)` before the comparison ensures numeric comparison works as intended.
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.
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.