tictactoe.py

#Game board
#----Global variables----

board=["-","-","-",
       "-","-","-",
       "-","-","-"]

#if game is still going
game_still_going=True
#who won? or tie?
winner=None

#whos turn is it
current_player="X"
#display the board
def display_board():
  print(board[0]+" | "+board[1]+" | "+board[2])
  print(board[3]+" | "+board[4]+" | "+board[5])
  print(board[6]+" | "+board[7]+" | "+board[8])
#play a game tic tac toe
def play_game():
  #display initial board
  display_board()
  #while the game is still going
  while game_still_going:
    #handle  a single turn of arbitrary player
    handle_turn(current_player)

    #check if the game has ended
    check_if_game_over()
    #flip to the other player
    flip_player()
  #The game has ended
  if winner=="X" or winner=="O":
    print(winner+" won. ")
  elif winner==None:
    print("Tie.")

def check_if_game_over():
  check_for_winner()
  check_if_tie()

def check_for_winner():
  #set up global variable
  global winner
  #checks rows
  row_winner=check_rows()

  #check columns
  column_winner=check_columns()
  #checks diagonals
  diagonal_winner=check_diagonals()

  if row_winner:
    #there was a win
    winner=row_winner
  elif column_winner:
    #there was a win
    winner=column_winner
  elif diagonal_winner:
    #there was a win
    winner=diagonal_winner
  else:
    #there was no win
    winner=None
  
  return

def check_rows():
  #set up global variable
  global game_still_going
  #check if any row has same values(not equal to -)
  row_1=board[0]==board[1]==board[2] !="-"
  row_2=board[3]==board[4]==board[5] !="-"
  row_3=board[6]==board[7]==board[8] !="-"
  # if  any row has a match ,flag that there is a win
  if row_1 or row_2 or row_3:
    game_still_going=False
  #return the winner X or O
  if row_1:
    return board[0]
  elif row_2:
    return board[3]
  elif row_3:
    return board[6]
  return


def check_columns():
  #set up global variable
  global game_still_going
  #check if any column has same values(not equal to -)
  column_1=board[0]==board[3]==board[6] !="-"
  column_2=board[1]==board[4]==board[7] !="-"
  column_3=board[2]==board[5]==board[8] !="-"
  # if  any column has a match ,flag that there is a win
  if column_1 or column_2 or column_3:
    game_still_going=False
  #return the winner X or O
  if column_1:
    return board[0]
  elif column_2:
    return board[1]
  elif column_3:
    return board[2]
  return

def check_diagonals():
   #set up global variable
  global game_still_going
  #check if any diagonal has same values(not equal to -)
  diagonal_1=board[0]==board[4]==board[8] !="-"
  diagonal_2=board[2]==board[4]==board[6] !="-"

  # if  any diagonal has a match ,flag that there is a win
  if diagonal_1 or diagonal_2:
    game_still_going=False
  #return the winner X or O
  if diagonal_1:
    return board[0]
  elif diagonal_2:
    return board[2]
  return

def check_if_tie():
  global game_still_going
  if "-" not in board:
    game_still_going=False
  return

def flip_player():
  #set up  global variable
  global current_player
  #changing current_player from O to X
  if current_player=="O":
    current_player="X"
  #changing current_player from X to O
  elif current_player=="X":
    current_player="O"
  return 


def handle_turn(player):
  print(player+"'s turn.")
  position=input("choose a position from 1-9 : ")

  valid =False
  while not valid: 
    while position not in ["1","2","3","4","5","6","7","8","9"]:        position=input("choose a position from 1-9 : ")
  
    position=int(position)-1
    if board[position]=="-":
      valid=True
    else:
      print("You can not go there..Go again.")
  board[position]=player
  display_board()

play_game()






#board
#display board
#play game
#check win
#check rows
#check columns
#check diagonal
#check Tie
#flip player