# Four-In-A-Row (a Connect Four clone) # http://inventwithpython.com/blog # By Al Sweigart al@inventwithpython.com import random import copy import sys BOARDWIDTH = 7 BOARDHEIGHT = 6 def main(): """ b = getNewBoard() b[6][5] = 'X' b[5][4] = 'X' b[4][3] = 'X' b[3][2] = 'X' drawBoard(b) print(isWinner(b, 'X')) sys.exit() """ print('Four-In-A-Row') print() while True: humanTile, computerTile = enterHumanTile() turn = whoGoesFirst() print('The %s player will go first.' % (turn)) mainBoard = getNewBoard() while True: if turn == 'human': drawBoard(mainBoard) move = getHumanMove(mainBoard) makeMove(mainBoard, humanTile, move) if isWinner(mainBoard, humanTile): winner = 'human' break turn = 'computer' else: drawBoard(mainBoard) print('The computer is thinking...') move = getComputerMove(mainBoard, computerTile) makeMove(mainBoard, computerTile, move) if isWinner(mainBoard, computerTile): winner = 'computer' break turn = 'human' if isBoardFull(mainBoard): winner = 'tie' break drawBoard(mainBoard) print('Winner is: %s' % winner) if not playAgain(): break def playAgain(): # This function returns True if the player wants to play again, otherwise it returns False. print('Do you want to play again? (yes or no)') return input().lower().startswith('y') def enterHumanTile(): # Let's the human player type which tile they want to be. # Returns a list with the human player's tile as the first item, and the computer's tile as the second. tile = '' while not (tile == 'X' or tile == 'O'): print('Do you want to be X or O?') tile = input().upper() # the first element in the tuple is the human player's tile, the second is the computer's tile. if tile == 'X': return ['X', 'O'] else: return ['O', 'X'] def drawBoard(board): print() print(' ', end='') for x in range(1, BOARDWIDTH + 1): print(' %s ' % x, end='') print() print('+---+' + ('---+' * (BOARDWIDTH - 1))) for y in range(BOARDHEIGHT): print('| |' + (' |' * (BOARDWIDTH - 1))) print('|', end='') for x in range(BOARDWIDTH): print(' %s |' % board[x][y], end='') print() print('| |' + (' |' * (BOARDWIDTH - 1))) print('+---+' + ('---+' * (BOARDWIDTH - 1))) def getNewBoard(): board = [] for x in range(BOARDWIDTH): board.append([' '] * BOARDHEIGHT) return board def getHumanMove(board): while True: print('Which column do you want to move on? (1-%s, or "quit" to quit game)' % (BOARDWIDTH)) move = input() if move.lower().startswith('q'): sys.exit() if not move.isdigit(): continue move = int(move) - 1 if isValidMove(board, move): return move def getComputerMove(board, computerTile): potentialMoves = getPotentialMoves(board, computerTile, 2) bestMoveScore = max([potentialMoves[i] for i in range(BOARDWIDTH) if isValidMove(board, i)]) bestMoves = [] for i in range(len(potentialMoves)): if potentialMoves[i] == bestMoveScore: bestMoves.append(i) return random.choice(bestMoves) def getPotentialMoves(board, playerTile, lookAhead): if lookAhead == 0: return [0] * BOARDWIDTH potentialMoves = [] if playerTile == 'X': enemyTile = 'O' else: enemyTile = 'X' # Returns (best move, average condition of this state) if isBoardFull(board): return [0] * BOARDWIDTH # Figure out the best move to make. potentialMoves = [0] * BOARDWIDTH for playerMove in range(BOARDWIDTH): dupeBoard = copy.deepcopy(board) if not isValidMove(dupeBoard, playerMove): continue makeMove(dupeBoard, playerTile, playerMove) if isWinner(dupeBoard, playerTile): potentialMoves[playerMove] = 1 break else: # do other player's moves and determine best one if isBoardFull(dupeBoard): potentialMoves[playerMove] = 0 else: for enemyMove in range(BOARDWIDTH): dupeBoard2 = copy.deepcopy(dupeBoard) if not isValidMove(dupeBoard2, enemyMove): continue makeMove(dupeBoard2, enemyTile, enemyMove) if isWinner(dupeBoard2, enemyTile): potentialMoves[playerMove] = -1 break else: results = getPotentialMoves(dupeBoard2, playerTile, lookAhead - 1) potentialMoves[playerMove] += (sum(results) / BOARDWIDTH) / BOARDWIDTH return potentialMoves def whoGoesFirst(): # Randomly choose the player who goes first. if random.randint(0, 1) == 0: return 'computer' else: return 'human' def makeMove(board, player, column): for y in range(BOARDHEIGHT-1, -1, -1): if board[column][y] == ' ': board[column][y] = player return def isValidMove(board, move): if move < 0 or move >= (BOARDWIDTH): return False if board[move][0] != ' ': return False return True def isBoardFull(board): for x in range(BOARDWIDTH): for y in range(BOARDHEIGHT): if board[x][y] == ' ': return False return True def isWinner(board, tile): # check horizontal spaces for y in range(BOARDHEIGHT): for x in range(BOARDWIDTH - 3): if board[x][y] == tile and board[x+1][y] == tile and board[x+2][y] == tile and board[x+3][y] == tile: return True # check vertical spaces for x in range(BOARDWIDTH): for y in range(BOARDHEIGHT - 3): if board[x][y] == tile and board[x][y+1] == tile and board[x][y+2] == tile and board[x][y+3] == tile: return True # check / diagonal spaces for x in range(BOARDWIDTH - 3): for y in range(3, BOARDHEIGHT): if board[x][y] == tile and board[x+1][y-1] == tile and board[x+2][y-2] == tile and board[x+3][y-3] == tile: return True # check \ diagonal spaces for x in range(BOARDWIDTH - 3): for y in range(BOARDHEIGHT - 3): if board[x][y] == tile and board[x+1][y+1] == tile and board[x+2][y+2] == tile and board[x+3][y+3] == tile: return True return False def playAgain(): # This function returns True if the player wants to play again, otherwise it returns False. print('Do you want to play again? (yes or no)') return input().lower().startswith('y') if __name__ == '__main__': main()