TicTacToe (text based) (Python recipe) by Brandon Martin

ActiveState Code (http://code.activestate.com/recipes/580723/)

#TicTacToe
#Written by Brandon Martin
#Digital Sol

import random

class BadInputError(Exception):
    pass

class LogicError(Exception):
    pass

#===========GAMEBOARDS===========#

blankBoard = {
    'UL' : ' ', 'UM' : ' ', 'UR' : ' ',
    'CL' : ' ', 'CM' : ' ', 'CR' : ' ',
    'BL' : ' ', 'BM' : ' ', 'BR' : ' ',
}

debugBoard = {
    'UL' : ' ', 'UM' : ' ', 'UR' : ' ',
    'CL' : ' ', 'CM' : ' ', 'CR' : ' ',
    'BL' : ' ', 'BM' : ' ', 'BR' : ' ',
}

invertedSpaces = {
    'LU' : 'UL', 'MU' : 'UM', 'RU' : 'UR',
    'LC' : 'CL', 'MC' : 'CM', 'RC' : 'CR',
    'LB' : 'BL', 'MB' : 'BM', 'RB' : 'BR',
}

#===========DEFINITIONS===========#

'''Spaces'''
spaces = ('UL','UM','UR','CL','CM','CR','BL','BM','BR')

'''Wins'''
oWin = ('O','O','O')
xWin = ('X','X','X')

'''Doubles'''
oDoubles = [(' ','O','O'),('O',' ','O'),('O','O',' ')]
xDoubles = [(' ','X','X'),('X',' ','X'),('X','X',' ')]

'''Input'''
possibleInput = [key for key in blankBoard]
for key in invertedSpaces:
    possibleInput.append(key)
    
'''Space Types'''
corners = ('UL','UR','BL','BR')
sides = ('CL','CR', 'UM', 'BM')

'''Space Inversions'''

horizontalFlip = {
    'UL' : 'UR','UR' : 'UL',
    'CL' : 'CR','CR' : 'CL',
    'BL' : 'BR','BR' : 'BL',
    }

verticalFlip = {
    'UL' : 'BL', 'UM' : 'BM', 'UR' : 'BR',
    'BL' : 'UL', 'BM' : 'UM', 'BR' : 'UR',
    }

#===========OBJECTS===========#

class ticBoard():

    def __init__(self, mode='blank', copyBoard=None):
        if mode == 'blank':
            self.board = {space:blankBoard[space] for space in blankBoard}
        elif mode == 'debug':
            self.board = {space:debugBoard[space] for space in debugBoard}
        elif mode == 'copy' and copyBoard != None:
            self.board = {space:copyBoard.board[space] for space in copyBoard.board}
            
    def draw(self):
        '''Draw board'''
        print()
        print('    L   M   R ')
        print('U:  {} | {} | {} '.format(self.board['UL'], self.board['UM'], self.board['UR']))
        print('   -----------')
        print('C:  {} | {} | {} '.format(self.board['CL'], self.board['CM'], self.board['CR']))
        print('   -----------')
        print('B:  {} | {} | {} '.format(self.board['BL'], self.board['BM'], self.board['BR']))
        print()

    def place(self, symbol, space):
        '''Places a symbol at the designated space.'''
        try:
            self.board[space] = symbol
        except:
            raise BadInputError("{} is not a valid space for {}.".format(space, symbol))

    def clear(self):
        '''Clears board of all symbols.'''
        self.board = {space:' ' for space in self.board}

    def fieldReport(self):
        '''Returns dictionary of triads.'''
        report = {}
        report[('UL','UM','UR')] = (self.board['UL'],self.board['UM'],self.board['UR'])
        report[('CL','CM','CR')] = (self.board['CL'],self.board['CM'],self.board['CR'])
        report[('BL','BM','BR')] = (self.board['BL'],self.board['BM'],self.board['BR'])
        report[('UL','CL','BL')] = (self.board['UL'],self.board['CL'],self.board['BL'])
        report[('UM','CM','BM')] = (self.board['UM'],self.board['CM'],self.board['BM'])
        report[('UR','CR','BR')] = (self.board['UR'],self.board['CR'],self.board['BR'])
        report[('UL','CM','BR')] = (self.board['UL'],self.board['CM'],self.board['BR'])
        report[('UR','CM','BL')] = (self.board['UR'],self.board['CM'],self.board['BL'])
        return report

    def returnDoubles(self, report):
        '''Filters out report to only include triads close to winning. ie "[X,X, ]" or '[O, ,O]"'''
        doubles = {}
        for triad in report:
            if report[triad] in oDoubles or report[triad] in xDoubles:
                doubles[triad] = report[triad]
        return doubles

    def checkWin(self):
        '''Returns True if there are three symbols in a row. False if otherwise.'''
        report = self.fieldReport()
        for triad in report:
            if report[triad] == oWin or report[triad] == xWin:
                return True
        return False

    def checkEntry(self, entry, selected):
        '''Returns the entry and whether or not it is valid.'''
        entry = entry.upper()
        if entry in invertedSpaces:
            entry = invertedSpaces[entry]
        if entry not in possibleInput:
            return {'valid':False,'entry':entry, 'message':'\n{} is not a valid entry!'}
        if entry not in selected:
            return {'valid':True,'entry':entry}
        else:
            return {'valid':False,'entry':entry, 'message':'\n{} has already been selected!'}

    def buildString(self, string):
        if len(string) != 9:
            print('String is not correct length. Reformatting will occur.')
        string = string[:9]
        while len(string) < 9:
            string += '0'
        for i in range(9):
            if string[i] == '0':
                self.board[spaces[i]] = ' '
            elif string[i] == '1':
                self.board[spaces[i]] = 'O'
            elif string[i] == '2':
                self.board[spaces[i]] = 'X'
            

    def blankSpaces(self):
        '''Returns list of free spaces remianing.'''
        return [space for space in self.board if self.board[space] == ' ']

class player():

    def __init__(self, identity):
        self.id = identity
        self.score = 0
        self.match = 0
        self.symbol = ''

    def setName(self, name):
        '''Define player's name.'''
        if 0 < len(str(name)) < 20:
            self.name = name.title()
            return False
        else:
            return True

    def setSymbol(self, symbol):
        if symbol.upper() in ['X','O']:
            self.symbol = symbol.upper()
            return False
        else:
            return True

    def win(self):
        self.score += 1

    def matchWin(self):
        self.match += 1

    def resetMatch(self):
        self.match = 0

    def getSymbol(self):
        return self.symbol

    def getName(self):
        return self.name

    def getIdentity(self):
        return self.id

    def getScore(self):
        return self.score

    def getMatches(self):
        return self.match

class computer(player):

    def __init__(self, difficulty='E'):
        self.id = 'comp'
        self.difficulty = difficulty[0]
        self.setName('Computer')
        self.setSymbol('X')
        self.score = 0
        self.match = 0
        self.strategy = ''
        self.tactic = ''
        self.lastMove = ''
        self.reiterate = False

    def mapCoordinates(self, triad):
        '''Converts a entry from a triad tuple to a dictionary of
           symbol : coordinate values.'''
        mapped = {}
        coor = 0
        for coordinate in triad[0]:
            mapped[coordinate] = triad[1][coor]
            coor+=1
        return mapped

    def analyzeMap(self, mappedCoordinates):
        '''Returns empty value from a mapped coordinates dictionary.'''
        for key in mappedCoordinates:
            if mappedCoordinates[key] == ' ':
                return key

    def defineStrategy(self, strategy):
        '''Play offensively (first turn) or defensively.'''
        if strategy in ['offensive','defensive']:
            self.strategy = strategy

    def decideTactic(self, board):
        '''Decide tactic based on the first move or by making first move.'''
        if self.strategy == 'offensive':
            firstMove = random.choice(['center','corner'])
            #firstMove = 'corner'
            self.tactic = firstMove
        elif self.strategy == 'defensive':
            for space in board.board:
                if board.board[space] == 'O':
                    if space in corners:
                        self.tactic = 'corner'
                    elif space == 'CM':
                        self.tactic = 'center'
                    else:
                        self.tactic = 'side'

    def clearStrategy(self):
        self.strategy = ''
        self.tactic = ''

    def counter(self, doubles):
        '''Either place winning piece or stop opponent from winning.'''
        if doubles != {}:
            triad = doubles.popitem()
            entry = self.analyzeMap(self.mapCoordinates(triad))
            debug(d,'Countering')
            return {'counter':True, 'entry':entry}
        return {'counter':False, 'entry':''}

    def trapSimulation(self, board, report, pool):
        '''Simulate different moves to trap opponent.'''
        for coordinate in pool:
            simulatedBoard = ticBoard('copy',board)
            simulatedBoard.place(self.getSymbol(),coordinate)
            simulatedDoubles = board.returnDoubles(simulatedBoard.fieldReport())
            soDoubles = {key:simulatedDoubles[key] for key in simulatedDoubles if 'O' in simulatedDoubles[key]}
            sxDoubles = {key:simulatedDoubles[key] for key in simulatedDoubles if 'X' in simulatedDoubles[key]}
            if len(soDoubles) == 0 and len(sxDoubles) > 1:
                debug(d,'Trapping')
                return {'trap':True, 'entry':coordinate}
        return {'trap':False, 'entry':coordinate}
        
    def offensiveStrategy(self, board):
        '''Provide offensive move based on a certain tactic.'''
        if self.tactic == 'center':
            if len(board.blankSpaces()) == 9:
                debug(d,'Begin Center')
                return {'offensive':True, 'entry':'CM'}
            elif len(board.blankSpaces()) == 7:
                for corner in corners:
                    if board.board[corner] == 'O' and board.board[verticalFlip[horizontalFlip[corner]]] == ' ':
                        debug(d,'Countering Corner')
                        return {'offensive':True, 'entry': verticalFlip[horizontalFlip[corner]]}
                return {'offensive':False, 'entry':''}
            else:
                return {'offensive':False, 'entry':''}
            
        elif self.tactic == 'corner':
            if len(board.blankSpaces()) == 9:
                debug(d,'Begin Corner')
                return {'offensive':True, 'entry':random.choice(corners)}
            else:
                if board.board['CM'] != 'O':
                    if self.lastMove != '':
                        if board.board[horizontalFlip[self.lastMove]] == ' ' and board.board[self.lastMove[0] + 'M'] != 'O':
                            debug(d,'Horizontal Flip')
                            return {'offensive':True, 'entry':horizontalFlip[self.lastMove]}
                        elif board.board[horizontalFlip[self.lastMove]] == 'O':
                            debug(d,'Invert')
                            return {'offensive':True, 'entry':verticalFlip[horizontalFlip[self.lastMove]]}
                        else:
                            debug(d,'Vertical Flip')
                            return {'offensive':True, 'entry':verticalFlip[self.lastMove]}
                if board.board['CM'] == 'O':
                    for space in board.board:
                        if board.board[space] == 'X' and space in corners:
                            debug(d,'Form XOX')
                            return {'offensive':True, 'entry':horizontalFlip[verticalFlip[space]]}

                else:
                    return {'offensive':False, 'entry':''} 
                
        
    def defensiveStrategy(self, board):
        '''Provide defensive move based on a certain tactic.'''
        if self.tactic == 'center': #Keep Selecting Corners
            for corner in corners:
                if board.board[corner] == ' ':
                    debug(d,'Get Corners')
                    return {'defense':True, 'entry':corner}
        elif self.tactic == 'corner':
            if board.board['CM'] == ' ': #Get Center
                debug(d,'Secure Center')
                return {'defense':True, 'entry':'CM'}
            else:
                if len(board.blankSpaces()) == 6:
                    cornersFound = 0
                    for corner in corners:
                        if board.board[corner] == 'O':
                            cornersFound += 1
                    if cornersFound == 2:
                        for side in sides:
                            if board.board[side] == ' ':
                                debug(d,'Two Corners')
                                return {'defense':True, 'entry':side}
                    else:
                        self.strategy = 'offensive'
                        self.tactic = 'center'
                        self.reiterate = True
                        debug(d,'Retrategizing')
                        return {'defense':False, 'entry':''}
        elif self.tactic == 'side':
            if board.board['CM'] == ' ': #Get Center
                return {'defense':True, 'entry':'CM'}
            else:
                if len(board.blankSpaces()) == 6:
                    report = board.fieldReport()
                    for triad in report:
                        if triad == ('O','X','O'):
                            debug(d,'OXO Kill')
                            return {'defense':True, 'entry':random.choice(corner)}
            
        return {'defense':False, 'entry':''} 

    def think(self, board):
        '''Return best possible move for a given situation.'''
        ### Query Board for Information ###
        while True:
            report = board.fieldReport()
            totalDoubles = board.returnDoubles(report)
            oDoubles = {key:totalDoubles[key] for key in totalDoubles if 'O' in totalDoubles[key]}
            xDoubles = {key:totalDoubles[key] for key in totalDoubles if 'X' in totalDoubles[key]}
            pool = board.blankSpaces()
            if pool == []:
                return

            ### Check for Winning Counters ###
            counterMove = self.counter(xDoubles)
            if counterMove['counter']:
                self.lastMove = counterMove['entry']
                return counterMove['entry']

            ### Check for Losing Counters ###
            counterMove = self.counter(oDoubles)
            if counterMove['counter']:
                self.lastMove = counterMove['entry']
                return counterMove['entry']
            
            ### Check for Trapping Moves ###
            trapMove = self.trapSimulation(board, report, pool)
            if trapMove['trap']:
                self.lastMove = trapMove['entry']
                return trapMove['entry']

            ### Strategize ###
            if self.strategy == '':
                if len(board.blankSpaces()) == 9:
                    self.strategy = 'offensive'
                else:
                    self.strategy = 'defensive'

            if self.tactic == '':
                self.decideTactic(board)

            if self.strategy == 'offensive':
                offenseMove = self.offensiveStrategy(board)
                if offenseMove['offensive']:
                    self.lastMove = offenseMove['entry']
                    return offenseMove['entry']
            else:
                defenseMove = self.defensiveStrategy(board)
                if defenseMove['defense']:
                    self.lastMove = defenseMove['entry']
                    return defenseMove['entry']

            ### Random Guess ###
            if self.reiterate:
                self.reiterate = False
            else:
                debug(d,'Random Entry')
                entry = random.choice(pool)
                self.lastMove = entry
                return entry

class debugger():

    def __init__(self):
        self.active = True

#===========HELPER FUNCTIONS===========#

def nextTurn(turnList, currentTurn):
    currentIndex = turnList.index(currentTurn)
    if (currentIndex + 1) == len(turnList):
        return turnList[0]
    else:
        return turnList[currentIndex+1]

def debug(debugObject,statement):
    if debugObject.active:
        print(statement)

#===========GAME FUNCTIONS=============#

d = debugger()

def TicTacToe(debugging=True):

    if not debugging:
        d.active = False

    ###MENUS###

    def mainMenu():
        difficulty = 'Easy'
        players = {}
        debugStatus = ''
        while True:
            if d.active:
                debugStatus = 'Enabled'
            else:
                debugStatus = 'Disabled'
            print('\t\tTic-Tac-Toe')
            print('\n\t1. One Player')
            print('\t2. Two Players')
            if players != {}:
                print('\t\tA. Rematch')
            print('\n\t3. Computer Difficulty:',difficulty)
            print('\t4. Debugging',debugStatus)
            
            selection = str(input('\nSelect Game Mode: '))
            while selection not in ['1', '2', '3', '4', 'A', 'a', 'escape']:
                print('\nSelection Invalid')
                selection = str(input('\nSelect Game Mode: '))
                
            if selection == '1':
                print()
                players = singlePlayer(difficulty)
                print()
                players = gameplay(players)

            elif selection == '2':
                print()
                players = multiPlayer()
                print()
                players = gameplay(players)

            elif selection == '3':
                print()
                if difficulty == 'Easy':
                    difficulty = 'Medium'
                elif difficulty == 'Medium':
                    difficulty = 'Hard'
                elif difficulty == 'Hard':
                    difficulty = 'Impossible'
                else:
                    difficulty = 'Easy'

            elif selection == '4':
                print()
                if d.active:
                    d.active = False
                else:
                    d.active = True

            elif selection in ['A','a']:
                if players != {}:
                    print()
                    players = gameplay(players)
                else:
                    print('Not an Option')

            elif selection == 'escape':
                break

            else:
                raise BadInputError('Data Provided Has No Function')

    def singlePlayer(difficulty):
        '''Returns dictionary of players for singleplayer gameplay.'''
        
        players = {}

        newPlayer = player('play1')
        print('Player 1',end=' ')
        if not d.active:
            nameEntry = str(input('please enter your name: '))
            while newPlayer.setName(nameEntry):
                print('Invalid Entry!')
                print('Player 1',end=' ')
                nameEntry = str(input('please enter your name: '))
        else:
            newPlayer.setName("Debug")
            
        newPlayer.setSymbol('O')
        players['play1'] = newPlayer
        players['comp'] = computer(difficulty)

        return players

    def multiPlayer():
        '''Returns dictionary of players for multiplayer gameplay.'''

        symbols = ['X','O']
        players = {}

        for identity in ['play1','play2']:
            
            if identity == 'play1':
                title = 'Player 1'
            else:
                title = 'Player 2'

            newPlayer = player(identity)
            print(title,end=' ')
            nameEntry = str(input('please enter your name: '))
            while newPlayer.setName(nameEntry):
                print('Invalid Entry!')
                print(title,end=' ')
                nameEntry = str(input('please enter your name: '))
            if identity == 'play1':
                symbolEntry = str(input('O or X: '))
                while newPlayer.setSymbol(symbolEntry):
                    print('Invalid Entry!')
                    symbolEntry = str(input('O or X: '))
                symbols.remove(symbolEntry.upper())
            else:
                newPlayer.setSymbol(symbols[0])
            players[identity] = newPlayer

        return players

    def gameplay(players):
        '''Provides turn system for a Tic Tac Toe Game.'''

        if 'comp' not in players:
            print('Beginning Game, {} vs {}'.format(players['play1'].getName(),players['play2'].getName()))
        else:
            print('Beginning Game, {} vs the Computer'.format(players['play1'].getName()))
        print("Win Two Matches In a Row to Be Victorious")
        
        board = ticBoard(mode='blank')
        
        turnList = list(players.keys())
        firstTurn = random.choice(turnList)
        #firstTurn = 'comp'
        turn = firstTurn
        selected = []

        while True:
            board.draw()
            if turn != 'comp':
                print(players[turn].getName(),'please select a space.')
                selection = str(input('Space: ')).upper()
                if not d.active or selection not in ["RESET", "END"]:
                    errorCheck = board.checkEntry(selection,selected)
                    while not errorCheck['valid']:
                        errorMessage = errorCheck['message'].format(selection)
                        print(errorMessage)
                        print(players[turn].getName(),'please select a space.')
                        selection = str(input('Space: ')).upper()
                        errorCheck = board.checkEntry(selection,selected)
                if selection == 'END':
                    break
                
            else:
                print('Computer Turn')
                selection = players['comp'].think(board)
                errorCheck = board.checkEntry(selection,selected)
                print('Computer Chooses {}'.format(selection))
                
            if selection != 'RESET' or not d.active:
                board.place(players[turn].getSymbol(), errorCheck['entry'])
                selected.append(selection)
            
            if board.checkWin() and selection != 'RESET':
                board.draw()
                selected = []
                winner = turn
                loser = nextTurn(turnList, turn)
                if players[winner].getMatches() == 1:
                    print(players[turn].getName(),end=' ')
                    str(input('wins!'))
                    players[turn].win()
                    players[loser].resetMatch()
                    players[winner].resetMatch()
                    break #END GAME
                elif players[winner].getMatches() == 0:
                    print(players[turn].getName(),end=' ')
                    players[winner].matchWin()
                    players[loser].resetMatch()
                    str(input('won a match! Beginning next round.'))
                    if 'comp' in players:
                       players['comp'].clearStrategy() 
                    board.clear()
                    turn = loser
                    firstTurn = loser
                
            else:
                if len(board.blankSpaces()) == 0 or selection == 'RESET':
                    board.draw()
                    str(input('Draw! Beginning next round.'))
                    if 'comp' in players:
                       players['comp'].clearStrategy() 
                    players[turn].resetMatch()
                    players[nextTurn(turnList, turn)].resetMatch()
                    board.clear()
                    firstTurn = nextTurn(turnList, firstTurn)
                    turn = firstTurn
                    selected = []
                else:
                    turn = nextTurn(turnList, turn)
                
        try: 
            print()
            print('\t\tCurrent Score\n')
            print('\t'+players[winner].getName()+'\t\t\t'+str(players[winner].getScore()))
            print('\t'+players[loser].getName()+'\t\t\t'+str(players[loser].getScore()))
            print('\n==========================================\n')
        except:
            print('\tNo Scores to Show.\n')

        return players

    mainMenu() #Load Main Menu First

activeDebug = False
TicTacToe(activeDebug) #Begin Program