tictactoe.py

player1 = "Spieler1"
player2 = "Spieler2"

def display():
    for y, line in enumerate(board):
        print(f"{line[0]}|{line[1]}|{line[2]}")
        if y < 2:
            print("-+-+-")
        
            

def is_valid(char):
    if char.lower() == "quit":
        return True
    if len(char) != 1:
        return False
    if char not in "123456789":
        return False
    for line in board:
        for number in line:
            if char == number:
                return True
    return False

board =[["1","2","3"], 
        ["4","5","6"],
        ["7","8","9"]]
       
turn_number = 1
display()
while turn_number < 10:
    if turn_number % 2 == 0:
        player = player2
        char = "o"
    else:
        player = player1
        char = "x"
    print(f"Runde {turn_number}:")
    while True:
        answer = input(f"Dein Spielzug {player}? (1-9) oder 'quit' >>>")
        if is_valid(answer):
            break
    if answer == "quit":
        break
    # ---- answer is correct -----
    # ----- update board ----
    for y, line in enumerate(board):
        for x, text in enumerate(line):
            if text == answer:
                board[y][x] = char
    # ----- print board ----
    display()
    # ------
    turn_number += 1

print("Danke fürs Spielen")