Tic Tac Toe victory check I am writing Python code for a Tic Tac Toe game.  I need to write a function that takes in three inputs: board, x, and y.  Board being the current display of the board and then x and y being values of 0, 1, or 2.  The game is set up to ask the user for coordinates.

def CheckVictory(board, x, y):

    #check if previous move was on vertical line and caused a win
    if board[0][y] == ('X') and board[1][y] == ('X') and board [2][y] == ('X'):
        return True
    if board[0][y] == ('O') and board[1][y] == ('O') and board [2][y] == ('O'):
        return True

    #check if previous move was on horizontal line and caused a win
    if board[x][0] == ('X') and board[x][1] == ('X') and board [x][2] == ('X'):
        return True
    if board[x][0] == ('O') and board[x][1] == ('O') and board [x][2] == ('O'):
        return True

    #check if previous move was on the main diagonal and caused a win
    if board[0][0] == ('X') and board[1][1] == ('X') and board [2][2] == ('X'):
        return True
    if board[0][0] == ('O') and board[1][1] == ('O') and board [2][2] == ('O'):
        return True
    #check if previous move was on the secondary diagonal and caused a win
    if board[0][2] == ('X') and board[1][1] == ('X') and board [2][0] == ('X'):
        return True
    if board[0][2] == ('O') and board[1][1] == ('O') and board [2][0] == ('O'):
        return True

    return False 
#end of CheckVictory function


The function is called in the game loop like so:

p_x, p_y = playerTurn(board)    #let player take turn
displayBoard(board)             #show board after move has been made
if CheckVictory(board, p_x, p_y):   #see if user has won
    print("CONGRATULATIONS, you win!")
    newGame(board)  #game over start new one
    continue


and it's similar for the computer turn.

I feel like there is a better way to write this function.  I feel like I should be using x and y more or there is a better way to check rather than writing all the possibilities. What's a better way to write this to make it short and concise?
You know that a mark has been placed at board[x][y]. Then you only need this to check for a win on vertical line y:

if board[0][y] == board[1][y] == board [2][y]


Your comments state "check if previous move was on the main/secondary diagonal", but you don't actually check. You can use the expressions x == y and x + y == 2 to check that.

Simplified code:

def CheckVictory(board, x, y):

    #check if previous move caused a win on vertical line 
    if board[0][y] == board[1][y] == board [2][y]:
        return True

    #check if previous move caused a win on horizontal line 
    if board[x][0] == board[x][1] == board [x][2]:
        return True

    #check if previous move was on the main diagonal and caused a win
    if x == y and board[0][0] == board[1][1] == board [2][2]:
        return True

    #check if previous move was on the secondary diagonal and caused a win
    if x + y == 2 and board[0][2] == board[1][1] == board [2][0]:
        return True

    return False