Tic Tac Toe Starter

from os import system
from cs50 import get_int

board = [1,2,3,4,5,6,7,8,9]

def print_board():
    print(f"{board[0]} | {board[1]} | {board[2]}")
    print(f"{board[3]} | {board[4]} | {board[5]}")
    print(f"{board[6]} | {board[7]} | {board[8]}")
    print()

def x_move():
    global board
    space = get_int("X move: ")
    if board[space - 1] != "X" and board[space - 1] != "O":
        board[space - 1] = "X"
        return True
    else:
        return False

def o_move():
    global board
    space = get_int("O move: ")
    if board[space - 1] != "X" and board[space - 1] != "O":
        board[space - 1] = "O"
        return True
    else:
        return False

def game_over():
    global board
    if board[0] == 'X' and board[1] == 'X' and board[2] == 'X':
        print("X wins!")
        return True
    #game over figures out if someone wins, or if the game is a draw
    #if the game is over, it prints out the result and returns True.
    #If not, it returns False.
    return False

system("clear")
print("Welcome to Tic Tac Toe")
while True:
    print_board()
    while True:
        if x_move():
            break
    if game_over():
        break
    system("clear")
    print_board()
    while True:
        if o_move():
            break
    if game_over():
        break
    system("clear")