Question 99 of 511
Exceptions and File I/OmediumMultiple ChoiceObjective-mapped

Quick Answer

The answer is None because the FileNotFoundError is not caught by the IOError handler. In Python 3, the exception hierarchy was reorganized: FileNotFoundError is a subclass of OSError, not IOError, which was deprecated and made an alias of OSError. When the code tries to open a nonexistent file, Python raises FileNotFoundError, but the except clause only specifies IOError, so the exception propagates unhandled, causing the program to terminate without printing anything. On the PCAP exam, this tests your understanding of the modern exception hierarchy and the common trap of assuming IOError still covers file-related errors. A key memory tip: in Python 3, think of OSError as the parent for all system-related errors, with FileNotFoundError, PermissionError, and IsADirectoryError as its children—IOError is just an alias, not a catch-all.

PCAP Exceptions and File I/O Practice Question

This PCAP practice question tests your understanding of exceptions and file i/o. 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.

Exhibit

Refer to the exhibit.

Exhibit:
    def parse_value(data):
        try:
            value = int(data)
            return value
        except ValueError:
            return None
        except TypeError:
            return None
        except:
            return -1
    
    result = parse_value('abc')
    print(result)

What will be printed?

Question 1mediummultiple choice
Full question →

Exhibit

Refer to the exhibit.

Exhibit:
    def parse_value(data):
        try:
            value = int(data)
            return value
        except ValueError:
            return None
        except TypeError:
            return None
        except:
            return -1
    
    result = parse_value('abc')
    print(result)

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

None

The code attempts to open a file for reading that does not exist, which raises a FileNotFoundError. Since the except clause only catches IOError, and FileNotFoundError is a subclass of OSError, not IOError (in Python 3), the exception is not caught. The program terminates with an unhandled exception, so nothing is printed, and the output is None.

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.

  • -1

    Why it's wrong here

    Would be if no specific except matched, but ValueError matches.

  • 0

    Why it's wrong here

    No conversion possible.

  • An exception is raised.

    Why it's wrong here

    Exception is caught.

  • None

    Why this is correct

    Correct: ValueError caught, returns None.

    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 exception class hierarchies, specifically that FileNotFoundError is not caught by IOError in Python 3, leading candidates to incorrectly assume the exception is handled and some value is printed.

Detailed technical explanation

How to think about this question

In Python 3, FileNotFoundError is a subclass of OSError, not IOError. The IOError class was merged into OSError in Python 3.3, so catching IOError does not catch FileNotFoundError. This is a common pitfall when porting code from Python 2, where IOError was a separate class. In real-world scenarios, always catch OSError or the specific exception (e.g., FileNotFoundError) to handle file I/O errors reliably.

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 cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.

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.

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FAQ

Questions learners often ask

What does this PCAP question test?

Exceptions and File I/O — This question tests Exceptions and File I/O — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: None — The code attempts to open a file for reading that does not exist, which raises a FileNotFoundError. Since the except clause only catches IOError, and FileNotFoundError is a subclass of OSError, not IOError (in Python 3), the exception is not caught. The program terminates with an unhandled exception, so nothing is printed, and the output is None.

What should I do if I get this PCAP 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.

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Last reviewed: Jun 30, 2026

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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.