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Level 0 / Project 04 - Yes No Questionnaire

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Try in Browser: Run this exercise online — no installation needed!

Before You Start

Recall these prerequisites before diving in: - Can you use .strip() and .lower() to clean up a string? - Can you check if a value is in a set? ("yes" in {"yes", "y", "true"})

Estimated time: 20 minutes

Learn Your Way

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Concept This project — Quiz Flashcards Diagram Browser

Focus

  • boolean logic and input normalization

Why this project exists

Process yes/no survey answers, normalise messy input like "YES", "y", "True" into clean booleans, and tally the results with percentages. You will learn input normalisation and basic statistics.

Run (copy/paste)

Use <repo-root> as the folder containing this repository's README.md.

cd <repo-root>/projects/level-0/04-yes-no-questionnaire
python project.py
pytest -q

The program asks you 5 questions interactively and tallies your answers.

Expected terminal output

=== Yes/No Questionnaire ===
Answer 5 questions with yes or no.

  1. Do you enjoy learning new things? yes
  2. Have you used a computer before today? y
  3. Do you like solving puzzles? yeah
  4. Are you excited to learn Python? YES
  5. Do you prefer working alone? no

=== Results ===
  Total responses: 5
  Yes: 4 (80.0%)
  No:  1 (20.0%)
  Invalid: 0
5 passed

Expected artifacts

  • Passing tests
  • Updated notes.md

Checkpoint: Baseline code runs and all tests pass. Commit your work before continuing.

Alter it (required) — Extension

  1. Add "maybe" as a third valid answer category (accept "maybe", "perhaps", "unsure").
  2. Add a percentage bar using # characters next to each tally count.
  3. Re-run script and tests.

Break it (required) — Core

  1. Answer every question with just spaces or blank -- does tally_answers() crash or return zeros?
  2. Answer with "YES!!!" or "y e s" -- does normalise_answer() handle them?
  3. What happens if you call tally_answers([]) with an empty list?

Fix it (required) — Core

  1. Handle the empty-answers case by returning a tally with all zeros.
  2. Strip punctuation from answers so "YES!!!" normalises to "yes".
  3. Add a test for the all-blank-answers edge case.

Checkpoint: All modifications done, tests still pass. Good time to review your changes.

Explain it (teach-back)

  1. Why does normalise_answer() use .strip().lower() before checking membership in a set?
  2. What is the difference between checking answer in {"yes", "y", "true"} vs using if/elif?
  3. Why return "invalid" for unrecognised answers instead of raising an error?
  4. Where would answer normalisation appear in real software (survey tools, form validation)?

Mastery check

You can move on when you can: - run baseline without docs, - explain one core function line-by-line, - break and recover in one session, - keep tests passing after your change.

Stuck? Ask AI

If you are stuck after trying for 20 minutes, use one of these prompts:

  • "I am working on Yes No Questionnaire. I got this error: [paste error]. Can you explain what this error means without giving me the fix?"
  • "I am trying to normalize messy input strings like 'YES', 'y', 'True' into a consistent format. Can you explain .strip().lower() with examples that are not about yes/no answers?"
  • "Can you explain how to calculate a percentage from a count and a total, with a simple example?"
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