- A
Write a custom parser that handles each router's output format individually.
Why wrong: Incorrect because this is not scalable and requires manual effort for each router.
- B
Use the 'split()' method to tokenize each line and then extract the relevant fields by position.
Why wrong: Incorrect because this is brittle and fails if the column order or spacing changes.
- C
Use the 'textfsm' library with a pre-defined template for 'show ip interface brief'.
Correct because textfsm templates are designed to handle variations in output format and provide structured data.
- D
Use the 're' module with a more complex regular expression that accounts for optional whitespace.
Why wrong: Incorrect because while this may help, it is still less robust than textfsm and harder to maintain.
Quick Answer
The best approach is to use the TextFSM library with a pre-defined template for 'show ip interface brief', as this directly addresses the need for robust parsing when output formats vary across devices. TextFSM works by defining a structured template that matches the expected output, allowing it to handle inconsistencies like extra spaces or altered column headers through its flexible state-machine logic, rather than relying on brittle regular expressions that break on minor format changes. On the ENCOR 350-401 exam, this question tests your understanding of network automation and parsing techniques, often appearing as a trap where candidates choose regex for its simplicity, forgetting that production environments demand scalability and resilience. A key memory tip is to think of TextFSM as a "template-based shield" that absorbs format variations, while regex is a "fixed scalpel" that cuts only one shape—always choose the shield for multi-vendor or multi-router parsing tasks.
350-401 Python for Network Automation Practice Question
This 350-401 practice question tests your understanding of python for network automation. Examine the command output carefully: the correct answer depends on what the output actually shows, not on general recall alone. 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.
An engineer is writing a Python script to parse the output of 'show ip interface brief' from multiple Cisco routers. The engineer uses the netmiko library to collect the output and then uses regular expressions to extract the interface name, IP address, and status. The script works correctly for most routers, but on one router, the output format is slightly different (e.g., extra spaces or different column headers). The engineer wants to make the parsing more robust. What is the best approach?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"best"Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
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
Use the 'textfsm' library with a pre-defined template for 'show ip interface brief'.
The correct answer is to use the 'textfsm' library with a pre-defined template for 'show ip interface brief'. Option A is incorrect because it is not scalable for many devices. Option B is incorrect because it does not handle format variations. Option D is incorrect because it does not change the parsing logic.
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.
- ✗
Write a custom parser that handles each router's output format individually.
Why it's wrong here
Incorrect because this is not scalable and requires manual effort for each router.
- ✗
Use the 'split()' method to tokenize each line and then extract the relevant fields by position.
Why it's wrong here
Incorrect because this is brittle and fails if the column order or spacing changes.
- ✓
Use the 'textfsm' library with a pre-defined template for 'show ip interface brief'.
Why this is correct
Correct because textfsm templates are designed to handle variations in output format and provide structured data.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Use the 're' module with a more complex regular expression that accounts for optional whitespace.
Why it's wrong here
Incorrect because while this may help, it is still less robust than textfsm and harder to maintain.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
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.
- Use explanations to understand the rule behind the answer.
TExam Day Tips
- Underline the problem statement mentally.
- 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 350-401 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 350-401 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
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Python for Network Automation — study guide chapter
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FAQ
Questions learners often ask
What does this 350-401 question test?
Python for Network Automation — This question tests Python for Network Automation — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Use the 'textfsm' library with a pre-defined template for 'show ip interface brief'. — The correct answer is to use the 'textfsm' library with a pre-defined template for 'show ip interface brief'. Option A is incorrect because it is not scalable for many devices. Option B is incorrect because it does not handle format variations. Option D is incorrect because it does not change the parsing logic.
What should I do if I get this 350-401 question wrong?
Identify which 350-401 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 18, 2026
This 350-401 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 350-401 exam.
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