How do i get a variable from a function? - python-3.x

Question

So I am a total noob at python so im sorry if im not being specific enough.
I am writing a tic tac toe program and the hardest thing is getting to switch turns
so i wrote a function to do this but i cant get the "turn" variable which belongs to another function. Im sorry if im being moronic but this is the best i can explain it. Thanks for your Time :)
BTW here is the code
x="X"
o="O"
EMPTY=" "
TIE="TIE"
NUM_SQUARES=9
def display_instruct():
print(
"""
Welcome to the greatest challenge ever
Tic
Tac
Toe
the board is as shown
0|1|2
------
3|4|5
-----
6|7|8
Prepare as teh game is about to start
""")
def yesno(question):
response=None
while response not in ("y","n"):
response=input(question).lower()
return response
def asknum(question, low, high):
response=None
while response not in range(low,high):
response=int(input(question))
return response
def pieces():
go_first=yesno("Do you want the first move")
if go_first=="y":
print("then take the first move you will need it")
human=x
computer=o
turn=x
return computer, human
else:
print ("Ok i shall go first")
computer=x
human=o
turn=x
return computer, human
def new_board():
board=[]
for square in range(NUM_SQUARES):
board.append(EMPTY)
return board
def display_board(board):
print ("\n")
print (board[0],"|",board[1],"|",board[2])
print ("----------")
print (board[3],"|",board[4],"|",board[5])
print ("----------")
print (board[6],"|",board[7],"|",board[8])
def legal_moves(board):
moves=[]
for square in range(NUM_SQUARES):
if board[square]==EMPTY:
moves.append(square)
return moves
def winner(board):
WAYS_TO_WIN=((0,1,2),(3,4,5),(6,7,8),(0,3,6),(1,4,7),(2,5,8),(0,4,8),(2,4,6))
for row in WAYS_TO_WIN:
if board[row[0]]==board[row[1]]==board[row[2]]!=EMPTY:
winner=[row[0]]
return winner
if EMPTY not in board:
return TIE
return None
def human_move(board,human):
legal=legal_moves(board)
move=None
print (legal)
while move not in legal:
move=asknum("Where will you move",0,NUM_SQUARES)
return move
def computer_move(board,computer,human):
board=board[:]
BEST_MOVES=(4,0,2,6,8,1,3,5,7)
print ("I shall take square number", end=" ")
for move in legal_moves(board):
board[move]=computer
if winner(board)==computer:
print(move)
return move
for move in legal_moves(board):
board[move]=human
if winner(board)==human:
print(move)
return move
board[move]=EMPTY
for move in BEST_MOVES:
if move in legal_moves(board):
print (move)
return move
def next_turn(turn):
if turn==x:
return o
else:
return x
def congrat_winner(the_winner,computer,human):
if the_winner!=TIE:
print(the_winner, "WON")
else:
print ("Its a ttie")
if the_winner==computer:
print ("I WON HA HA IN YO FACE")
elif the_winner==human:
print ("NO IT CANNOT BE")
elif the_winner==TIE:
print ("you were lucky this time")
def curturn(turn,computer,human):
if turn==x and move!="" and move!=" ":
turn=o
elif turn==o and move!="" and move!=" ":
turn=x
def main():
display_instruct()
computer, human=pieces()
turn=x
board=new_board()
display_board(board)
curturn(turn,computer,human)
while not winner (board):
display_board(board)
if turn == human:
move=human_move(board,human)
board[move]=human
else:
move=computer_move(board,computer,human)
board[move]=computer
display_board(board)
turn=next_turn(turn)
the_winner=winner(board)
congrat_winner(the_winner,computer,human)
main()

Answer 1

Functions look like this (simplified):
def functionname(parameter1, parameter2=foo):
code that does stuff
return value
If you in your function want to access a variable from the calling function, you pass it in as a parameter. If you from the calling function want to access a variable from the function you call, you return it.
You can also use global variable (which you do, I see) and that is a Bad Idea, as it will make your program messy and hard to debug. So avoid that if you can (although in a small program like this, it's not a disaster, so don't bother now).
If you want to access variables from completely different places, you probably want to look into object-oriented programming, with classes and stuff.