初学者问题，编写我的第一个代码。 不确定这个问题

Question

I'm a beginner coder learning how to use Python and writing my first tic-tac-toe code.

FirstQ = input("Welcome to Tic Tac Toe!" + "\n" + "Player 1: Do you want to be X or O? ")

def place_marker(): #This function will now attempt to place an X onto the board
if FirstQ == "X":
    player1 = FirstQ
    player2 = "O"
elif FirstQ == "O":
    player1 == FirstQ
    player2 == "X"

So what I am trying to do is once a player selects whether they're either X or O. I'm trying to assign that to the player.

When I type X, the code runs fine but if I type OI get the following error:

Traceback (most recent call last):
File "D:/Python/Projects/TIC TAC TOE.py", line 46, in <module>

place_marker()



File "D:/Python/Projects/TIC TAC TOE.py", line 36, in place_marker


UnboundLocalError: local variable 'player1' referenced before assignment

Can someone explain how this works?

Here is the entire code that I've done so far:

#Global Variables
testboard = ([' ',' ',' ',' ',' ',' ',' ',' ',' '])
player1 = input("Welcome to Tic Tac Toe!" + "\n" + "Player 1: Do you want to be X or O? ")

def display_board(board): #Function for designing the board
    print ('   |   |   ')
    print ('{}  | {} | {} '.format(board[6],board[7],board[8])) #This is where the X and O will go
    print ("   |   |   ")
    print ("-----------")
    print ("   |   |   ")
    print ('{}  | {} | {} '.format(board[3],board[4],board[5])) #This is where the X and O will go
    print ("   |   |   ")
    print ("-----------")
    print ("   |   |   ")
    print ('{}  | {} | {} '.format(board[0],board[1],board[2])) #This is where the X and O will go
    print ("   |   |   ")

    pass

def player_input(): #Function for assigning the player whether they will be X or O
    if player1 == "X":
        return ("Player 1 will start first as X")
    elif player1 == "O":
        return ("Player 1 will start first as O")
   # else:
        #return ("Sorry, please enter in either X or O"  ||Work on this Later
        #print (player_input())

def place_marker(): #This function will now attempt to place an X onto the board
    if player1 == "X":
        player2 = "O"
    elif player1 == "O":
        player2 == "X"

    print ("The positions on the Tic Tac Toe will be similar to that of the Numpad. ")
    Marker1 = input("Please enter a number between 1 - 9 to place your {} in the corresponding position ".format(player1))


print (player_input())
print ("\n")
display_board(testboard)
place_marker()

Answer 1

Change

   player1 == FirstQ
   player2 == "X"

to

  player1 = FirstQ
  player2 = "X"