My code

import os
import time
import keyboard

loop_exit = False


def clear_output(player_names=True):
    global player1, player2
    os.system("cls")
    print("Welcome to my TicTacToe game. \nIn this game, your objective is to get three of your own symbols in a row before the other player does so.\n")

    if not player_names:
        return

    print(f"Hello, {player1} and {player2}. {player1}, you will be X and {player2}, you will be O.")


def get_name(player_num, symbol):
    global player1
    while True:
        alpha_num = True

        player = input(f"Q: What is your name Player {player_num} ({symbol})?\n"
                       "A: I am ").strip()

        if not player:
            alpha_num = False

        for i in range(len(player)):
            if not player[i].isalpha() and not player[i].isdigit():
                alpha_num = False

        if not alpha_num:
            print("Invalid name! Please enter only letters and/or numbers.")
            time.sleep(2)
            clear_output(False)
            continue
        elif len(player) > 25:
            print("The name is too long! Enter a short version of the name.")
            time.sleep(2)
            clear_output(False)
            continue
        elif player_num == 2 and player == player1:
            print("Both player names cannot be the same! Please make it a bit different.")
            time.sleep(2)
            clear_output(False)
            continue

        clear_output(False)
        break

    return player


def rules_and_board():
    global player1, player2
    player1_turn = True
    cell1 = cell2 = cell3 = cell4 = cell5 = cell6 = cell7 = cell8 = cell9 = " "
    counter = 0

    while True:
        print(f'''Each player will go one by one. {player1}, you will go first and {player2}, you will go second. \n
You will see a drawing board in front of you and to place a symbol on the board you have to type in the number of the desired box you want to place your '''
              '''symbol in, as displayed below.
      |     |
   1  |  2  |  3
 _____|_____|_____
      |     |
   4  |  5  |  6
 _____|_____|_____
      |     |
   7  |  8  |  9
      |     |    \n\n ''')

        if not counter:
            print("Press enter to continue...")
            keyboard.wait("enter")
            counter += 1
            clear_output()
            continue

        print(f'''      |     |
   {cell1}  |  {cell2}  |  {cell3}
 _____|_____|_____
      |     |
   {cell4}  |  {cell5}  |  {cell6}
 _____|_____|_____
      |     |
   {cell7}  |  {cell8}  |  {cell9}
      |     |     \n''')

        if (cell1 == cell2 == cell3 != " " or cell4 == cell5 == cell6 != " " or cell7 == cell8 == cell9 != " " or cell1 == cell4 == cell7 != " " or
                cell2 == cell5 == cell8 != " " or cell3 == cell6 == cell9 != " " or cell1 == cell5 == cell9 != " " or cell3 == cell5 == cell7 != " "):
            if player1_turn:
                print(f"Well done, {player1}. You have won against {player2}.")
            else:
                print(f"Well done, {player2}. You have won against {player1}.")
            break
        else:
            player1_turn = not player1_turn

        try:
            if player1_turn:
                chosen_cell = int(input(f"Your move {player1}: "))
            else:
                chosen_cell = int(input(f"Your move {player2}: "))

            if chosen_cell not in range(1, 10):
                raise ValueError()

        except ValueError:
            print("Invalid number! Your reply can only be a number between 1-9 (incl.)")
            clear_output()
            continue

        if chosen_cell == 1:
            if player1_turn:
                cell1 = "X"
            else:
                cell1 = "O"
        elif chosen_cell == 2:
            if player1_turn:
                cell2 = "X"
            else:
                cell2 = "O"
        elif chosen_cell == 3:
            if player1_turn:
                cell3 = "X"
            else:
                cell3 = "O"
        elif chosen_cell == 4:
            if player1_turn:
                cell4 = "X"
            else:
                cell4 = "O"
        elif chosen_cell == 5:
            if player1_turn:
                cell5 = "X"
            else:
                cell5 = "O"
        elif chosen_cell == 6:
            if player1_turn:
                cell6 = "X"
            else:
                cell6 = "O"
        elif chosen_cell == 7:
            if player1_turn:
                cell7 = "X"
            else:
                cell7 = "O"
        elif chosen_cell == 8:
            if player1_turn:
                cell8 = "X"
            else:
                cell8 = "O"
        elif chosen_cell == 9:
            if player1_turn:
                cell9 = "X"
            else:
                cell9 = "O"

        clear_output()


print("Welcome to my TicTacToe game. \nIn this game, your objective is to get three of your own symbols in a row before the other player does so.\n"
      "Press enter to continue...")
keyboard.wait("enter")

while not loop_exit:
    clear_output(False)
    player1 = get_name(1, "X")
    player2 = get_name(2, "O")
    clear_output()

    rules_and_board()

    while True:
        play_again = input("Q: Do you want to play again? (Y/N)\n"
                           "A: ")

        if play_again.lower() not in ["y", "n"]:
            print("Invalid reply! Please type a 'Y' for yes or a 'N' for no.")
            continue
        elif play_again.lower() == "n":
            print("Thanks for playing!")
            time.sleep(1)
            loop_exit = True
            break
        else:
            break