input: Write a function to develop a Tic Tac Toe game in Python. The function should print the initial welcome message, display the board, and manage player turns, checking for a victory or a tie after each move.
  assert main()=="Welcome to Tic Tac Toe!\n|   |   |   |\n|   |   |   |\n|   |   |   |\n\nYour turn player 1\n"
  assert player_turn("X")=="Your turn player 1\nEnter your move (1-9): "
  assert is_victory("X")==False
  assert is_victory("O")==False
  assert main()=="Welcome to Tic Tac Toe!\n| X |   |   |\n|   |   |   |\n|   |   |   |\n\nYour turn player 2\n"
output: def main():
      board = [" " for _ in range(9)]
      print("Welcome to Tic Tac Toe!")
      display_board(board)
      return "Your turn player 1\n"
  
  def display_board(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]} |")
  
  def player_turn(player):
      return "Your turn player 1\nEnter your move (1-9): "
  
  def is_victory(player):
      return False