This is a fiddly but straightforward function which draws the nine empty squares and also a panel at the bottom listing the valid characters for user input. __show_level

Noughts and Crosses: Oxford Modern Playscripts : Cooke Noughts and Crosses: Oxford Modern Playscripts : Cooke

If it is starting the game the computer will always select the centre square. Otherwise it uses a list of win paths which I'll describe in a moment to find the optimum square. The stages it goes through are:

That's the NaC class finished so now we can move on to writing a UI. As I mentioned above I have written a console UI with curses but the NaC class has no user interface code so can be used with any library or framework, for example PyGame, Tkinter, PyQt or whatever. This is one of the functions passed to the NaC class's __init__, and is called by the NaC class when either the computer or the user make a move. It therefore just needs to draw an "X" or "O" in the correct square. on_game_over

Noughts and Crosses in Python - CodeDromeCodeDrome Noughts and Crosses in Python - CodeDromeCodeDrome

Not essential as I could just use arbitrary numbers or strings but it does make the code neater. __init__ The average level uses either idiot level or genius level at random with 50:50 probability. __computer_move_genius In idiot mode the computer searches at random for an empty square to place its "O" in. __computer_move_averageThis is the other function passed to the NaC class and is called when the game is over. The winner argument is "X" for the player, "O" for the computer or " " for a draw. The function uses this to create a suitable message which is then displayed in an orange box in the middle of the board. For this make a function for game to restart. Define replay() function, which will take input from the player to play again or not. def replay(): Next the players’ marker are made by creating player_input()function by using while loop for player 1 to choose his/her marker; X or O. Once the marker has been chosen by player 1, then the alternate marker is automatically allotted to player 2 using if function. def player_input():

Noughts + Crosses OMITTED EXT. CROSS HOSPITAL - DAY 11 4AS01 Noughts + Crosses OMITTED EXT. CROSS HOSPITAL - DAY 11 4AS01

Here we set the counts of each possible state per win path for use by __computer_move_genius as described above. __find_empty_square Showing the level is done by a separate function so it can be called without redrawing the whole game. on_game_changed Consolidate all the above functions together to create the game. Start with whileloop, which creates an infinite loop, the code keeps on executing as long as a given boolean condition evaluates to true. Set up the board, assign player1_markerand player2_markeras player_input()where the players decide their markers and assign first_move()as turn that decides which player will go first. Initiate the game taking input from the player. If ready to play, enter Yes or No. If the player enters yes, then the game starts. Players are asked which position they want to mark so on and so forth. Once the game is finished, option is offered whether they want to replay or not. while True: This function creates a list of nine dictionaries representing the nine possible win paths, ie straight lines of three squares. Each dictionary contains the row/column numbers of the three squares as well as the counts of each of the three possible states of a square: empty, "O" and "X". __populate_win_paths The nac.py file contains a class implementing the game logic, independently of any user interface. The nacconsole.py file contains a class providing a console-based UI using curses. I wrote an introduction to curses a while ago which you might like to read before this article.

Start making the tic-tac-toe grid by defining display_board()function, which will display it in a grid format when printed def display_board(board):