How to create a Tic-Tac-Toe game in Python
Tic-Tac-Toe (also known as Noughts and Crosses) is a classic paper-and-pencil game people enjoy. The aim of the game is to be the first player to form a horizontal, vertical, or diagonal line of three marks (either X or O) on a grid. This Answer will walk you through creating a Tic-Tac-Toe game using Python. By following the step-by-step instructions below, you can build your very own interactive Tic-Tac-Toe game that you can play with other people.
Setting up the game board
The first step is to create the game board, essentially a grid where players make their moves. We’ll use a list of lists to represent the board and initialize it with empty spaces.
We’ll also create a function display_board() that will display the game board on the console. This function will iterate through the board and print the current state of each cell.
# Create the game boardboard = [[' ', ' ', ' '],[' ', ' ', ' '],[' ', ' ', ' ']]def display_board():print('-' * 5)for row in board:print('|'.join(row))print('-' * 5)
Handling player’s input
Let’s implement a function allowing players to enter their moves. We’ll prompt the players to enter their desired move’s row and column numbers and validate the input to ensure it’s within the valid range.
def get_player_move():while True:try:row = int(input("Enter the row number (0-2): "))column = int(input("Enter the column number (0-2): "))if 0 <= row <= 2 and 0 <= column <= 2:return row, columnelse:print("Invalid input. Please enter numbers between 0 and 2.")except ValueError:print("Invalid input. Please enter numbers.")
Updating game board
Once the players make their moves, we need to update the game board accordingly. We’ll modify the board state based on the player’s move and ensure the cell is not already occupied.
def update_board(row, column, player):if board[row][column] == ' ':board[row][column] = playerreturn Trueelse:return False
Checking for a winner
After each move, we’ll check if any player has won the game. We’ll define a function that examines the board state and determines if a winning combination of marks is in any row, column, or diagonal.
def check_winner():# Check rowsfor row in board:if row[0] == row[1] == row[2] != ' ':return row[0]# Check columnsfor col in range(3):if board[0][col] == board[1][col] == board[2][col] != ' ':return board[0][col]# Check diagonalsif board[0][0] == board[1][1] == board[2][2] != ' ':return board[0][0]if board[0][2] == board[1][1] == board[2][0] != ' ':return board[0][2]return None
Handling the game loop
To create a complete game experience, we’ll wrap the gameplay logic in a loop until there’s a winner or the game ends in a draw. We’ll alternate between players and prompt them for their moves inside the loop.
def play_game():current_player = 'X'while True:display_board()print(f"Player {current_player}'s turn.")row, column = get_player_move()if update_board(row, column, current_player):winner = check_winner()if winner:display_board()print(f"Player {winner} wins!")breakelif all(board[i][j] != ' ' for i in range(3) for j in range(3)):display_board()print("It's a draw!")breakcurrent_player = 'O' if current_player == 'X' else 'X'else:print("That cell is already occupied. Try again.")
Let's combine all this logic and see the code in action:
# Create the game board
board = [[' ', ' ', ' '],
[' ', ' ', ' '],
[' ', ' ', ' ']]
def display_board():
for row in board:
print('|'.join(row))
print('-' * 5)
def get_player_move():
while True:
try:
row = int(input("Enter the row number (0-2): "))
column = int(input("Enter the column number (0-2): "))
if 0 <= row <= 2 and 0 <= column <= 2:
return row, column
else:
print("Invalid input. Please enter numbers between 0 and 2.")
except ValueError:
print("Invalid input. Please enter numbers.")
def update_board(row, column, player):
if board[row][column] == ' ':
board[row][column] = player
return True
else:
return False
def check_winner():
# Check rows
for row in board:
if row[0] == row[1] == row[2] != ' ':
return row[0]
# Check columns
for col in range(3):
if board[0][col] == board[1][col] == board[2][col] != ' ':
return board[0][col]
# Check diagonals
if board[0][0] == board[1][1] == board[2][2] != ' ':
return board[0][0]
if board[0][2] == board[1][1] == board[2][0] != ' ':
return board[0][2]
return None
def play_game():
current_player = 'X'
while True:
display_board()
print(f"Player {current_player}'s turn.")
row, column = get_player_move()
if update_board(row, column, current_player):
winner = check_winner()
if winner:
display_board()
print(f"Player {winner} wins!")
break
elif all(board[i][j] != ' ' for i in range(3) for j in range(3)):
display_board()
print("It's a draw!")
break
current_player = 'O' if current_player == 'X' else 'X'
else:
print("That cell is already occupied. Try again.")
play_game()That’s it! We’ve successfully built a fully functional Tic-Tac-Toe game in Python.
