functions-explained-quiz.py

"""
Quiz: Functions Explained
Review: concepts/functions-explained.md
"""

from _quiz_helpers import normalize_answer, ask_true_false, ask_code_completion


def run_quiz():
    print("=" * 60)
    print("  QUIZ: Functions Explained")
    print("  Review: concepts/functions-explained.md")
    print("=" * 60)
    print()

    score = 0
    total = 9

    # Question 1
    print("Question 1/9: What keyword defines a function in Python?")
    print()
    print("  a) function")
    print("  b) func")
    print("  c) def")
    print("  d) define")
    print()
    answer = normalize_answer(input("Your answer: "))
    if answer == "c":
        score += 1
        print("Correct! The 'def' keyword is used to define functions.")
    else:
        print("Incorrect. The answer is c) def.")
        print("Python uses 'def' (short for define) to create functions.")
    print()

    # Question 2
    print("Question 2/9: What will this code print?")
    print()
    print("  def add(a, b):")
    print("      result = a + b")
    print()
    print("  total = add(3, 5)")
    print("  print(total)")
    print()
    print("  a) 8")
    print("  b) None")
    print("  c) Error")
    print("  d) 0")
    print()
    answer = normalize_answer(input("Your answer: "))
    if answer == "b":
        score += 1
        print("Correct! The function calculates the result but never")
        print("returns it. Without a return statement, functions return None.")
    else:
        print("Incorrect. The answer is b) None.")
        print("The function is missing 'return result'. Without return,")
        print("Python returns None by default.")
    print()

    # Question 3
    print("Question 3/9: In this function definition, what is 'name'?")
    print()
    print("  def greet(name):")
    print('      return f"Hello, {name}!"')
    print()
    print("  a) An argument")
    print("  b) A parameter")
    print("  c) A variable")
    print("  d) A string")
    print()
    answer = normalize_answer(input("Your answer: "))
    if answer == "b":
        score += 1
        print("Correct! Parameters are the names in the function definition.")
        print("Arguments are the values you pass when calling the function.")
    else:
        print("Incorrect. The answer is b) parameter.")
        print("In the definition, it is a parameter. When you call")
        print("greet('Alice'), 'Alice' is the argument.")
    print()

    # Question 4
    print("Question 4/9: What will this code print?")
    print()
    print('  def greet(name, greeting="Hello"):')
    print('      return f"{greeting}, {name}!"')
    print()
    print('  print(greet("Alice"))')
    print()
    print('  a) Error — missing argument')
    print('  b) Hello, Alice!')
    print('  c) None, Alice!')
    print('  d) Alice')
    print()
    answer = normalize_answer(input("Your answer: "))
    if answer == "b":
        score += 1
        print("Correct! greeting has a default value of 'Hello', so you")
        print("can call the function with just one argument.")
    else:
        print("Incorrect. The answer is b) Hello, Alice!")
        print("The greeting parameter has a default value, so it is optional.")
    print()

    # Question 5
    print("Question 5/9: What is wrong with this code?")
    print()
    print('  greet("Alice")')
    print()
    print("  def greet(name):")
    print('      return f"Hello, {name}!"')
    print()
    print("  a) Nothing — it works fine")
    print("  b) NameError — greet is called before it is defined")
    print("  c) SyntaxError — wrong order")
    print("  d) TypeError — wrong argument type")
    print()
    answer = normalize_answer(input("Your answer: "))
    if answer == "b":
        score += 1
        print("Correct! Functions must be defined before they are called.")
        print("Python reads top to bottom.")
    else:
        print("Incorrect. The answer is b) NameError.")
        print("You must define a function before calling it.")
    print()

    # Question 6
    print("Question 6/9: What is the difference between these two lines?")
    print()
    print("  greet")
    print('  greet("Alice")')
    print()
    print("  a) They are the same")
    print("  b) greet is the function object; greet('Alice') calls it")
    print("  c) greet prints the function; greet('Alice') runs it")
    print("  d) Both call the function")
    print()
    answer = normalize_answer(input("Your answer: "))
    if answer == "b":
        score += 1
        print("Correct! Without parentheses, you are referencing the")
        print("function object itself. With parentheses, you call it.")
    else:
        print("Incorrect. The answer is b).")
        print("Parentheses () are what actually call the function.")
    print()

    # Question 7
    print("Question 7/9: Why are functions useful? (Pick the best answer)")
    print()
    print("  a) They make code run faster")
    print("  b) They let you reuse code, organize logic, and test pieces")
    print("     independently")
    print("  c) Python requires them")
    print("  d) They use less memory")
    print()
    answer = normalize_answer(input("Your answer: "))
    if answer == "b":
        score += 1
        print("Correct! Functions enable reuse, organization, testability,")
        print("and readability.")
    else:
        print("Incorrect. The answer is b).")
        print("Functions help with reuse, organization, testing, and clarity.")
    print()

    # Question 8 — true/false
    if ask_true_false(
        question_num=8,
        total=total,
        statement="A function can return more than one value using a tuple.",
        correct=True,
        explanation_correct="return x, y packs the values into a tuple that the caller can unpack.",
        explanation_incorrect="Python lets you write return x, y which returns a tuple (x, y). The caller can unpack it: a, b = my_func().",
    ):
        score += 1

    # Question 9 — code completion
    if ask_code_completion(
        question_num=9,
        total=total,
        prompt="Complete the function so it returns the square of n:",
        code_lines=[
            "def square(n):",
            "    ____ n * n",
        ],
        correct_answers=["return"],
        explanation_correct="The return keyword sends a value back to the caller.",
        explanation_incorrect="Use the return keyword to send a value back from a function.",
        case_sensitive=True,
    ):
        score += 1

    # Final score
    print("=" * 60)
    pct = round(score / total * 100)
    print(f"  Final Score: {score}/{total} ({pct}%)")
    print()
    if pct == 100:
        print("  Perfect! You understand functions well.")
    elif pct >= 70:
        print("  Good work! Review the questions you missed.")
    else:
        print("  Keep practicing! Re-read concepts/functions-explained.md")
        print("  and try again.")
    print("=" * 60)


if __name__ == "__main__":
    run_quiz()