This is a pythom implementation of tic tac toe.

tictactoe.py

import pygame
import numpy as np
import sys

# initializing
pygame.init()
gameover = False

# board initialization
board = np.zeros((3,3), dtype=int)

# player initialization
player = 1

# mark colors
COLOR = ((0,0,0),(255,255,255))
# functions to draw the separating lines
def bars(screen, BG_COLOR, start, end, width):
    pygame.draw.line( screen, BG_COLOR, start, end, width)

# function to draw the circle
def circle(screen, center, radius, width ):
    center = tuple(i*200+100 for i in center)
    pygame.draw.circle(screen, (255,255,255), center, radius, width)

# function to draw cross
def cross(screen, center, size, width ):
    center = tuple(i*200+100 for i in center)
    start_1 = tuple(i-j for i,j in zip(center,size))
    end_1 = tuple(i+j for i,j in zip(center, size))
    # size = tuple(i*j for i,j in zip(size,()))
    start_2 = tuple(i-j*k for i,j,k in zip(center,size,(-1,1)))
    end_2 = tuple(i+j*k for i,j,k in zip(center, size,(-1,1)))
    
    bars(screen, (0,0,0), start_1, end_1, width)
    bars(screen, (0,0,0), start_2, end_2, width)

# function to check if the cell is marked
def isMarked(pos):
    if board[pos]:
        return True
    return False

# function to check if the board is filled
def isFilled(board):
    if (board==0).any():
        return False
    return True

# to check if a player won
def win(board):
    if ((board == 1).all(axis=1)).any():
        return True
    elif ((board == 2).all(axis=1)).any():
        return True
    elif ((board == 1).all(axis=0)).any():
        return True
    elif ((board == 2).all(axis=0)).any():
        return True
    elif (board.diagonal()==1).all():
        return True
    elif (board[::-1].diagonal()==1).all():
        return True
    elif (board.diagonal()==2).all():
        return True
    elif (board[::-1].diagonal()==2).all():
        return True
    else:
        return False

# dimensions of board
DIMENSIONS = (600,600)
# purple
BG_COLOR = (179,102,255)

# dimensions are 600*600 fixed
screen = pygame.display.set_mode(DIMENSIONS)

# caption 
pygame.display.set_caption("TIC TAC TOE")

# background color
screen.fill(BG_COLOR)

# making the horizontal and vertical separting bars
bars(screen, tuple(2*i//3 for i in BG_COLOR), (15,200), (595,200), 15)
bars(screen, tuple(2*i//3 for i in BG_COLOR), (15,400), (595,400), 15)
bars(screen, tuple(2*i//3 for i in BG_COLOR), (200,15), (200,585), 15)
bars(screen, tuple(2*i//3 for i in BG_COLOR), (400,15), (400,585), 15)


while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        if event.type == pygame.MOUSEBUTTONDOWN and not gameover:
            pos = event.pos
            pos = tuple(i//200 for i in pos)
            if not isMarked(pos):
                board[pos] = player
                if player == 1: circle(screen, pos, 75, 15 )
                if player == 2: cross(screen, pos, (60,60),20) 
                if win(board):
                    print("player {} won the game".format(player))
                    gameover = True
                if isFilled(board):
                    print("Tie")
                    gmaeover = True
                player = (player % 2) + 1


    pygame.display.update()