JSON Project — Quiz from a JSON File

By the end of this project you can:

• Design a JSON schema for quiz questions.
• Validate the loaded JSON before running the quiz.
• Score the player, then save the score in a separate JSON file.
• Show all-time stats by reading the score history.

Load the file, then check it's shaped how the engine expects. Fail loudly if not.

import json

def load_quiz(path):
    with open(path, encoding="utf-8") as f:
        data = json.load(f)

    # Validate
    if "questions" not in data or not isinstance(data["questions"], list):
        raise ValueError("Missing or invalid 'questions' list")

    for i, q in enumerate(data["questions"]):
        for key in ("q", "options", "answer"):
            if key not in q:
                raise ValueError(f"Question {i + 1} missing '{key}'")
        if not isinstance(q["options"], list) or len(q["options"]) < 2:
            raise ValueError(f"Question {i + 1} needs at least 2 options")
        if not isinstance(q["answer"], int):
            raise ValueError(f"Question {i + 1} answer must be an int")
        if not (0 <= q["answer"] < len(q["options"])):
            raise ValueError(f"Question {i + 1} answer index out of range")

    return data

Loading is one line; validating is the rest. Real apps validate every external input — assume the file is wrong until it proves otherwise.

import random

def run_quiz(quiz):
    print(f"\n=== {quiz['title']} ===")
    questions = quiz["questions"][:]
    random.shuffle(questions)              # different order each run

    score = 0
    for i, q in enumerate(questions, start=1):
        print(f"\nQ{i}: {q['q']}")
        for j, opt in enumerate(q["options"]):
            print(f"  {j + 1}. {opt}")
        while True:
            try:
                pick = int(input("Your answer (number): ")) - 1
                if 0 <= pick < len(q["options"]):
                    break
            except ValueError:
                pass
            print("  ! Pick a valid number.")
        if pick == q["answer"]:
            print("  ✓ Correct!")
            score += 1
        else:
            correct = q["options"][q["answer"]]
            print(f"  ✗ Wrong. Answer was: {correct}")

    print(f"\nFinal score: {score} / {len(questions)}")
    return score, len(questions)

One pure function. It takes a quiz dict, returns (score, total). Easy to test, easy to wrap.

After each quiz, append a record to scores.json.

from datetime import datetime

def save_score(quiz_title, name, score, total):
    try:
        with open("scores.json", encoding="utf-8") as f:
            history = json.load(f)
    except FileNotFoundError:
        history = []

    history.append({
        "quiz": quiz_title,
        "name": name,
        "score": score,
        "total": total,
        "when":  datetime.now().isoformat(timespec="seconds"),
    })

    with open("scores.json", "w", encoding="utf-8") as f:
        json.dump(history, f, indent=2)

def show_stats():
    try:
        with open("scores.json", encoding="utf-8") as f:
            history = json.load(f)
    except FileNotFoundError:
        print("(no history yet)")
        return

    print(f"\n=== All-Time Scores ({len(history)} entries) ===")
    for h in history[-10:]:
        pct = round(h["score"] / h["total"] * 100)
        print(f"  {h['when']}  {h['name']:<12} {h['quiz']:<24} "
              f"{h['score']}/{h['total']} ({pct}%)")

JSON turns "configuration" from code into data. The quiz engine is one file; the quiz content is another. Schools, libraries and tutoring apps work exactly this way — one engine, many quiz files. Validation catches typos in the file before they corrupt the user's experience. Scores persist across runs. The pattern scales: same shape works for a flashcard app, a vocabulary trainer, a study deck.