- A
with open('config.json', 'r') as f:\n data = f.read()
Using with ensures proper acquisition and release of resources.
- B
open('config.json', 'r') as f:\n data = f.read()
Why wrong: Missing the 'with' keyword; syntax error.
- C
with open('config.json', 'r') as f, data = f.read()
Why wrong: Syntax error; cannot assign variable inside with statement like that.
- D
file = open('config.json', 'r')\ndata = file.read()\nfile.close()
Why wrong: This manually closes the file but does not guarantee closure if an exception occurs before file.close().
Question 629 of 1,000
200-901 Software Development and Design Practice Question
This 200-901 practice question tests your understanding of software development and design. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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 writes a Python script to read a configuration file. Which code snippet correctly opens the file 'config.json' for reading and ensures the file is closed after use?
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
✓
with open('config.json', 'r') as f:\n data = f.read()
Option A is correct because it uses the `with` statement, which is a context manager that automatically calls `f.close()` when the block exits, ensuring the file is properly closed even if an exception occurs. The `'r'` mode opens the file for reading, and `f.read()` reads the entire contents into the `data` variable.
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.
- ✓
with open('config.json', 'r') as f:\n data = f.read()
Why this is correct
Using with ensures proper acquisition and release of resources.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
open('config.json', 'r') as f:\n data = f.read()
Why it's wrong here
Missing the 'with' keyword; syntax error.
- ✗
with open('config.json', 'r') as f, data = f.read()
Why it's wrong here
Syntax error; cannot assign variable inside with statement like that.
- ✗
file = open('config.json', 'r')\ndata = file.read()\nfile.close()
Why it's wrong here
This manually closes the file but does not guarantee closure if an exception occurs before file.close().
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the candidate's understanding of Python's context manager (`with` statement) versus manual file handling, expecting candidates to recognize that only the `with` statement guarantees automatic resource cleanup, while explicit `close()` calls are error-prone in the face of exceptions.
Trap categories for this question
Keyword trap
Missing the 'with' keyword; syntax error.
Detailed technical explanation
How to think about this question
The `with` statement in Python implements the context manager protocol via the `__enter__` and `__exit__` methods. For file objects, `__exit__` calls `f.close()` even if an exception is raised, making it the recommended pattern for file I/O. In real-world scenarios, such as reading configuration files in a web server, failing to close files can exhaust file descriptors, leading to crashes or denial of service.
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 200-901 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.
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FAQ
Questions learners often ask
What does this 200-901 question test?
Software Development and Design — This question tests Software Development and Design — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: with open('config.json', 'r') as f:\n data = f.read() — Option A is correct because it uses the `with` statement, which is a context manager that automatically calls `f.close()` when the block exits, ensuring the file is properly closed even if an exception occurs. The `'r'` mode opens the file for reading, and `f.read()` reads the entire contents into the `data` variable.
What should I do if I get this 200-901 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: Jul 4, 2026
This 200-901 practice question is part of Courseiva's free Cisco 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 200-901 exam.
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