PCPP1 Best Practices And Coding Conventions Practice Question
When implementing secure coding practices in a web-facing Python application, how should you handle raw user input to prevent command injection?
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
✓
Pass input arguments as a list to subprocess.run(args, shell=False).
Using the 'subprocess' module with 'shell=False' (the default) prevents the shell from interpreting user-provided strings as commands.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Pass the entire input string to os.system().
Why it's wrong here
os.system() is inherently vulnerable to shell injection.
- ✗
Concatenate the input string into a shell command for execution.
Why it's wrong here
This leads to command injection vulnerabilities.
- ✓
Pass input arguments as a list to subprocess.run(args, shell=False).
Why this is correct
This approach treats the input as data rather than an executable command string.
- ✗
Sanitize input using a custom regex to remove special characters.
Why it's wrong here
Blacklisting is prone to bypasses; structural separation is safer.
About these practice questions
This PCPP1 question is part of Courseiva's 209-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official Python Institute exam blueprint
This PCPP1 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 PCPP1 exam.