Tic Tac Toe function not defining variable correctly

Question

I'm building a Tic Tac Toe game as practice for an intro-to-Python course I'm taking on Udemy. I have a series of functions built right now but I can't get two of them to work together. When I run these two functions I get an error saying the first_player is undefined. However, first_player is defined in the first function. Does anyone know why Python won't recognize what first_player is in the second function?

If these functions work correctly I'd expect it to as the first player if he/she wants to be X's or O's and then have Python assign X's or O's to player 1 and player 1.

In the choose_first player() I've tried printing out the first_player variable and it prints correctly.

The code I'm using is below:

#Randomly chooses which player goes first.
def choose_first_player():
    import random
    first_player = (str(random.randint(1,2)))

    if first_player == '1':
        print("\nPlayer " +first_player+ " goes first.")
    if first_player == '2':
        print("\nPlayer " +first_player+ " goes first.")

choose_first_player()

#Asks first_player if they want to be X's or O's.
def player_input():

    marker = ''

    while marker != 'X' and marker != 'O':
        marker = input("\nPlayer" +first_player+ " , do you want to be X's or O's?  Please enter X or O: ").upper()

    player1 = marker

    if player1 == 'X':
        player2 = 'O'
    else:
        player2 = 'X'
        player1 = 'O'

    print("\nPlayer 1 is: " + player1)
    print("Player 2 is: " + player2)
    return(player1,player2)

player_input()

You should read that link and some more about the [scope of variables in Python](https://www.google.com/search?q=python+variable+scope). Your problem is that the `first_player` is defined inside `choose_first_player()` and therefore isn't accessible elsewhere. — Pranav Hosangadi, Oct 20 '20 at 16:07
Yes, it does answer my question, thanks! I guess when I was trying to google an answer I didn't know I was looking for "Scope". That explains everything. Thank you again. — Hiebs915, Oct 20 '20 at 18:29

AlexisG · Accepted Answer · 2020-10-20T16:07:58.980

1

You can't access the variable of another function. (or you have to define it as a global variable)

choose_first_player can return the value of first_player and then you can pass it to the other function.

And do something like this :

def choose_first_player():
    ...
    return first_player

first_player = choose_first_player()

... 

def player_input(first_player):
  ...

player_input(first_player)

Here you can read more on python scopes

edited Oct 20 '20 at 16:07

answered Oct 20 '20 at 16:06

AlexisG

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This question is asked a thousand times. Please don't answer duplicates. – Pranav Hosangadi Oct 20 '20 at 16:07
Thanks for code and the link. They both helped explain things. I didn't know I was looking for a "scope" problem when I started googling this. Thanks again. – Hiebs915 Oct 20 '20 at 18:30

Tic Tac Toe function not defining variable correctly

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