Build a science quiz game in Python

The science idea

Materials and tools

Tools

• Python 3 and its editor (IDLE)
• A folder for the project, named quiz
• Pen and paper for the flowchart
• A phone or a notebook for the test plan

Safety first

Parts and layout

These drawings show the parts and how they fit together. Keep them beside you while you build.

Step-by-step build

13 steps. Do them in order, and test each part before you go on to the next.

1. Install and test Python

   Ask an adult to install Python 3 from python.org if it is not already on the computer. On Windows, tick “Add Python to PATH” in the installer. Open IDLE, and type the line below, and press Enter. If it prints a message, Python works.

   print("Hello, Python!")

   Tip: The IDLE window with the three arrows >>> is called the shell. Use File, New File to open an editor window for your program.

2. Plan with a flowchart

   On paper, draw the flowchart of the game: Start, ask the name, shuffle the questions, for each question show it, get a valid answer, check it, show a fact, then show the score and ask to play again. Compare it with the flowchart diagram on this page.

   Common mistake: Starting to type code before planning. If you do not know the steps in order, the code gets confused too.

3. Create the file and say hello

   In IDLE choose File, New File and save it as quiz.py in your quiz folder. Type the lines below and run them with F5 (Run, Run Module). It should ask your name and say hello.

   print("Welcome to the Science Quiz!")
   player = input("What is your name? ").strip() or "Player"
   print("Hello,", player)

   Tip: input() always gives you text. The .strip() removes spaces at the ends, and “or Player” uses a default name if the player just presses Enter.

4. Store the questions

   Make a list of questions. Each question is a dictionary with the question text, a list of four options, the number of the right option (counting from 1) and a fact. Type two questions first and add more later.

   questions = [
       {"q": "Which planet is known as the Red Planet?",
        "options": ["Venus", "Mars", "Jupiter", "Mercury"],
        "answer": 2,
        "fact": "Mars looks red because its soil contains iron oxide."},
       {"q": "What is the SI unit of force?",
        "options": ["Joule", "Pascal", "Newton", "Watt"],
        "answer": 3,
        "fact": "One newton gives a mass of 1 kg an acceleration of 1 m/s per second."},
   ]

   Common mistake: Forgetting a comma between two dictionaries or between two lines of one dictionary. A missing comma is the most common error in a list of data.

5. Write the function that asks a question

   A function groups lines of code under a name. This one prints a question and its options, then loops until the player types 1, 2, 3 or 4, and returns True if the answer is right. Keep the lines inside the function indented by four spaces.

   def ask_question(item, number):
       print()
       print("Question", number, ":", item["q"])
       for i, option in enumerate(item["options"], start=1):
           print("  ", i, ")", option)
       while True:
           choice = input("Your answer (1-4): ").strip()
           if choice in ("1", "2", "3", "4"):
               return int(choice) == item["answer"]
           print("Please type 1, 2, 3 or 4.")

   Tip: enumerate(list, start=1) gives each item together with a counter that starts from 1, so the options are numbered the way people count.

6. Write the game loop

   Write a loop that goes through the questions one by one. It adds 1 to the score if the answer is right, and shows the right answer if not. Put the lines below after the function. Run it and play.

   import random
   random.shuffle(questions)
   score = 0
   for number, item in enumerate(questions, start=1):
       if ask_question(item, number):
           print("Correct!")
           score += 1
       else:
           right = item["options"][item["answer"] - 1]
           print("Not quite. The answer is:", right)
       print("Fact:", item["fact"])
   print(player + ", you scored", score, "out of", len(questions))

   Common mistake: Writing = when you mean ==. A single = stores a value in a variable. A double == compares two values.

7. Fix errors by reading them

   If Python prints an error, read the last line and the line number. SyntaxError means a missing bracket, quote or colon. IndentationError means the spaces are wrong. NameError means a name was misspelt. Fix one error at a time and run again.

   Tip: Python reports where it noticed the problem, which is sometimes one line after the real mistake. Check the line before it too.

8. Add a message for the result

   Replace the last line with a result using if, elif and else. It calculates a percentage and prints one of three messages.

   percent = score * 100 / len(questions)
   if percent == 100:
       print("Perfect score!")
   elif percent >= 60:
       print("Well done!")
   else:
       print("Keep practising.")

   Tip: Python tests the conditions from top to bottom and runs only the first one that is true.

9. Save and load the best score

   Add two functions that read and write a file called best_score.txt. The try and except block stops the program from crashing the first time, when the file does not exist.

   def load_best():
       try:
           with open("best_score.txt") as f:
               return int(f.read().strip())
       except (FileNotFoundError, ValueError):
           return 0
   
   
   def save_best(score):
       with open("best_score.txt", "w") as f:
           f.write(str(score))

   Common mistake: Writing the file without converting the number to text. f.write() needs a string, so use str(score).

10. Time the player and put the game in a function

    Put the game loop in a function play(name) that also records the time with time.time() at the start and at the end. Then wrap it in a while loop that asks “Play again?”. The complete program is given in the last step.

    Tip: Test each new piece before you add the next. If something breaks, you know it is the last thing you added.

11. Write a test plan and test

    Fill in the test table: try a right answer, a wrong one, the letter x, an empty entry, the number 5, all right, all wrong, and playing twice. Write what you expected and what happened.

    Common mistake: Testing only the answers that work. Real users type unexpected things, so test them too.

12. Add your own questions

    Add at least 10 questions of your own from your textbook. Check each fact. Make sure that the answer number matches the position of the right option, counting from 1.

    Tip: A good quiz has options that look possible. Avoid silly wrong options.

13. The complete program

    This is the whole program with 10 questions. Read each part and compare it with your own. Then change it: add questions, change the grading, or add a hint.

    # Science Quiz Game: a small program with questions, scoring and a best score.
    import random
    import time
    
    questions = [
        {"q": "Which planet is known as the Red Planet?",
         "options": ["Venus", "Mars", "Jupiter", "Mercury"], "answer": 2,
         "fact": "Mars looks red because its soil contains a lot of iron oxide, which is rust."},
        {"q": "Which gas do plants take in from the air to make food?",
         "options": ["Oxygen", "Carbon dioxide", "Nitrogen", "Hydrogen"], "answer": 2,
         "fact": "In photosynthesis plants use carbon dioxide, water and light to make glucose and oxygen."},
        {"q": "What is the chemical formula of water?",
         "options": ["H2O", "CO2", "O2", "NaCl"], "answer": 1,
         "fact": "A molecule of water has two hydrogen atoms and one oxygen atom."},
        {"q": "Which force pulls objects towards the Earth?",
         "options": ["Friction", "Gravity", "Magnetism", "Tension"], "answer": 2,
         "fact": "Gravity gives every object weight. Weight = mass x g."},
        {"q": "What is the SI unit of electric current?",
         "options": ["Volt", "Ohm", "Ampere", "Watt"], "answer": 3,
         "fact": "One ampere is one coulomb of charge passing a point every second."},
        {"q": "Which organ pumps blood around the body?",
         "options": ["Lungs", "Heart", "Liver", "Kidney"], "answer": 2,
         "fact": "The human heart beats about 70 times a minute at rest."},
        {"q": "At sea level, at what temperature does water boil?",
         "options": ["50 degrees C", "100 degrees C", "0 degrees C", "150 degrees C"], "answer": 2,
         "fact": "Water boils at a lower temperature on a mountain because the air pressure is lower."},
        {"q": "Which metal is a liquid at room temperature?",
         "options": ["Iron", "Mercury", "Copper", "Zinc"], "answer": 2,
         "fact": "Mercury is a liquid metal, but its vapour is poisonous, so we avoid it."},
        {"q": "About how long does sunlight take to reach the Earth?",
         "options": ["8 seconds", "8 minutes", "8 hours", "8 days"], "answer": 2,
         "fact": "Light travels about 300,000 km every second, so it takes about 8 minutes."},
        {"q": "What is the SI unit of force?",
         "options": ["Joule", "Pascal", "Newton", "Watt"], "answer": 3,
         "fact": "One newton is the force that gives a mass of 1 kg an acceleration of 1 m/s per second."},
    ]
    
    
    def load_best():
        try:
            with open("best_score.txt") as f:
                return int(f.read().strip())
        except (FileNotFoundError, ValueError):
            return 0
    
    
    def save_best(score):
        with open("best_score.txt", "w") as f:
            f.write(str(score))
    
    
    def ask_question(item, number):
        print()
        print("Question", number, ":", item["q"])
        for i, option in enumerate(item["options"], start=1):
            print("  ", i, ")", option)
        while True:
            choice = input("Your answer (1-4): ").strip()
            if choice in ("1", "2", "3", "4"):
                return int(choice) == item["answer"]
            print("Please type 1, 2, 3 or 4.")
    
    
    def play(name):
        random.shuffle(questions)
        score = 0
        start = time.time()
        for number, item in enumerate(questions, start=1):
            if ask_question(item, number):
                print("Correct!")
                score += 1
            else:
                right = item["options"][item["answer"] - 1]
                print("Not quite. The answer is:", right)
            print("Fact:", item["fact"])
        seconds = round(time.time() - start)
        percent = score * 100 / len(questions)
        print()
        print(name + ", you scored", score, "out of", len(questions), "in", seconds, "seconds.")
        if percent == 100:
            print("Perfect score!")
        elif percent >= 60:
            print("Well done!")
        else:
            print("Keep practising.")
        best = load_best()
        if score > best:
            save_best(score)
            print("New best score!")
        else:
            print("Best score so far:", best)
    
    
    print("Welcome to the Science Quiz!")
    player = input("What is your name? ").strip() or "Player"
    while True:
        play(player)
        again = input("Play again? (y/n): ").strip().lower()
        if again != "y":
            break
    print("Thanks for playing,", player + "!")

    Tip: Put comments (lines starting with #) in your own version to explain each part in your own words. They are very useful in your report.

How it should look when it is finished

This is a description, not a photograph. Compare your own model with it and with the figures above.

How it works

Troubleshooting

Test and record

Run the program for each test. Write what you expect to happen before you try it, and what really happened. Mark pass or fail. Fix the program and test again if it fails.

Copy the table into your notebook and write each reading as you take it, in pencil, with the date. Repeat every test at least three times and use the average. Then draw a graph or chart of your results.

Viva questions and answers

A teacher or a judge will ask you how your project works. Practise these eight questions and answer them in your own words.

1. What is a variable?

   A name that refers to a value stored in the computer’s memory, such as score = 0. The value can change as the program runs.

2. What is the difference between a list and a dictionary?

   A list is an ordered collection accessed by position (item[0]); a dictionary stores values under names, called keys (item["q"]).

3. What is the difference between = and ==?

   A single = assigns a value to a variable. A double == compares two values and gives True or False.

4. What is a function and why use one?

   A named block of code that can be used again. It avoids repetition, makes the program easier to read and to fix, and can take inputs and return a result.

5. Why does indentation matter in Python?

   It shows which lines belong to a loop, an if or a function. Wrong indentation changes the meaning or causes an error.

6. What is input validation and where did you use it?

   Checking that the user’s input is acceptable before using it. In ask_question() the loop keeps asking until the answer is 1, 2, 3 or 4.

7. What does try and except do?

   It lets the program handle an error instead of crashing. If reading the best-score file fails, the program uses 0.

8. What is a flowchart and what do the diamond and the rectangle mean?

   A diagram of the steps of a program. A rectangle is an action, a diamond is a decision with two exits (yes and no), and rounded boxes are the start and the end.

Free ebook: Viva Questions for Science Projects

Written report outline

Use these headings in your project file, and write each part in your own words. Add a title page, your diagrams, the precautions you took and the books or sites you used.

Aim

To design, write and test a quiz game in Python that uses lists, dictionaries, loops, decisions, functions and a file.

Apparatus

A computer with Python 3 and IDLE, a notebook, and a flowchart drawn on paper.

Procedure

Describe how you planned the flowchart, wrote the program step by step, tested each part, and fixed errors. Include the flowchart, the program with comments and the test table.

Observation

The test table of expected and actual results, and a screenshot of the program running.

Result

The finished program asks ... questions, handles wrong input without crashing, saves the best score, and passed all ... tests.

Conclusion

A program is built from small parts: data, decisions, loops and functions. Planning with a flowchart and testing with a plan make a program correct and reliable.

Free ebook: Writing a Science Project File

Take it further

• Add a hint option: if the player types h, the program shows two wrong options removed.
• Put the questions in a separate file (for example questions.txt) so that a teacher can add questions without editing the program.
• Give a different score for easy and difficult questions and show the total points.
• Add a timer for each question and take away points if the player is too slow.
• Make a graphical version with the tkinter module that comes with Python.

Free ebooks, kits and help

Free ebooks for this project

• ProgrammingFreePython for BeginnersFree ebook · PDFGurukul Technicals Institute

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• ProgrammingFreeFlowcharts, Algorithms and Logic BuildingFree ebook · PDFGurukul Technicals Institute

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• ProgrammingFreeData Structures Made SimpleFree ebook · PDFGurukul Technicals Institute

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