Download Let's Code a Game: Tic Tac Toe! and more Exams Printing in PDF only on Docsity!
Let’s Code a Game: Tic Tac Toe!
Today we’re going to be making a text based version of the game Tic Tac Toe, also known as "Naughts and Crosses".
Part 0: Getting set up!
To get started first we need to create a file where we are going to write the code for our game.
- In your Python 3 IDLE click File and create a New File.
- Start by saving your file and calling it tictactoe.py
Now when you want to run your code, just click Run (or press F5 on the keyboard)!
Great! Now we’re ready to code!
Part 1: Printing the grid
In order to play Tic Tac Toe, we are going to need to print out the game board.
We want to print a grid that looks like this:
| 1 | 2 | 3 |
| 4 | 5 | 6 |
| 7 | 8 | 9 |
Each square has a number in it so we can tell the computer which square we want!
To do this, we'll need to use print. Want a hint on how to print? Look at your cheat sheet!
Task 1.
In your file tictactoe.py write some code that will print out the grid above.
Hint: You might need to use multiple print statements Hint: There are 13 dashes in the first line, Hint: What happens when you multiply a character by a number?
Part 2: Storing the players’ names
We need to remember the name of the two players. Let’s store each name in a variable.
Use input to ask each player for their name and store them in variables. (add it above your printer).
Task 2.
Before you print the grid, ask these 2 questions using input to get the names of the players: ● "Who will be naughts? " ● "Who will be crosses? "
Name your variables player0 for naughts and playerX for crosses.
Now you have the names, you'll need to show them!
Task 2.
Print a message welcoming both of the players by their name. Here's an example of how your code should run: Who will be naughts? Julia Who will be crosses? Maddie Welcome Julia and Maddie!
Remember how we learnt to add strings together? We’ll need to do that here to add all the names and text together!
Part 3: Storing the game
We’re going to store our game board in lists!
When we start the game we have no naughts or crosses. Remember we started out by printing a grid with the numbers 1-9 in it.
| 1 | 2 | 3 |
| 4 | 5 | 6 |
| 7 | 8 | 9 |
Let’s store these numbers in our list to start with. Later they will be replaced with X’s and O’s.
Part 5: The first turn of the game!
Now we are getting to the exciting part! We get to start making the game playing part! To put a piece down, we need to know two things: ● Whether it is a O or an X ● Where the O or X goes
Asking for the symbol
We need to find out what symbol to use when a player takes a square. When you play naughts and crosses you will be using ‘X’ and ‘O’, but really, you can put in anything.
Task 5.
- Ask the player what symbol to place using input.
- Store it in a variable named input_symbol_._
Ask which square they want to take
The next thing we need to do is find out which square the player wants to put their symbol in. We can do this using input.
Task 5.
- Show the players which squares are still available by printing out the grid. Any squares with numbers in them are free and can be selected.
- Then ask them which square they want to take using input. Store it in a variable named input_square_._
Turning that input into a useful number!
We now know which square the player wants to take. It’s stored in input_square; the only problem is it’s not a number, it’s a string!!
We can’t do maths or counting using a symbol (even though it is a number symbol)! We need to convert it to a number first.
Task 5.
Transform input_square to a number and store it in a new variable input_square_int Hint: Do you remember how we used int() to turn a string into a number?
Updating grid
Before we can update grid with the symbol to play we need to work out which item in the list we want to update. This is a bit tricky because we need to start counting from 0.
------------- Count from 0! | 1 | 2 | 3 | 0 1 2 3 4 5 6 7 8
| 4 | 5 | 6 | ["1", "2", "3", "4", "5", "6", "7", "8", "9"]
| 7 | 8 | 9 |
We can see that the indexes don’t quite line up with the numbers in our grid because we have to start counting from 0 when using a list.
When we want to put a X in square 1, that is actually item 0 in the list. If we want to put a X in square 9 that is actually item 8 in the list.
Putting an X in square 9: ------------- Count from 0! | 1 | 2 | 3 | 0 1 2 3 4 5 6 7 8
| 4 | 5 | 6 | ["1", "2", "3", "4", "5", "6", "7", "8", "X"]
| 7 | 8 | X |
For the example above, input_square_int is 9 but we want grid_index to be 8. We just need to write some code to do that for us. (P.S. "Index" is the name we give to a position in a list!)
Task 5.
We need to find the index that corresponds to the value in input_square_int and store it in grid_index. So if the user wants to edit square 5, grid_index should be 4.
Which of these options do you think will work? a. grid_index = input_square_int - 1 b. grid_index = input_square_int - 2 c. grid_index = input_square_int + 1 d. grid_index = input_square_int + 2
Add it to your code after you get input_square_int
Now we know which list item we need to update! Let’s get updating!
Goal: Update the the chosen index of grid to the chosen symbol
Part 6: Now repeat!
Now we have finished one turn of the game. The rest of the game is basically just doing the same thing over and over again!
But writing out all of that code again would be boring and computer programmers are known for being lazy! So instead we are going to use a while loop to make our code run for more than one turn!
Goal: Use a while loop to make the game continue for 9 turns.
Task 6.
Above the code you wrote for Part 5 , set up a variable to keep track of how many turns it has been and call it turns. At the start of the game there has been 0 turns.
Task 6.
- Create the while loop. Tell the while loop to run until there has been 9 turns.
- Indent your code from Part5 and Part6 to be inside your while loop.
Task 6.
Inside the loop you just created, at the end of the turn, update the number of turns it’s been. Hint use maths!
Bonuses:
- Try playing a game, but chose a square that’s already taken!
- Try playing only X’s and no O’s
- What happens if you play only on the same spot? When does the game finish?
When you write a program you can rig it however you want! To make it unriggable we need more code!
Are you finished with all of this?
Let a tutor know. We’ve got more stuff for you!
