Tic Tac Toe using Tkinter

[dmacch24]

I'm trying to write a program using Tkinter that makes the computer play against you. In this code, the computer wins everytime using the minimax algorithm. Is there a way for the first computer choice to be random and THEN for it to use minimax algorithm after so that there is still a chance to beat computer?

from Tkinter import *

from tkMessageBox import *

#board
#0 1 2
#3 4 5
#6 7 8

turn='X' #first turn

computer="O"
user="X"

#possible winning combinations
wins=[[0,1,2],[3,4,5],[6,7,8],[0,3,6],[1,4,7],[2,5,8],[0,4,8],[2,4,6]]

board=[" "]*9 #initialize board to all blanks

Labels={}

def addLabel(frame,text,x,y): #creates the labels for X and 0
label = Label(frame,text=text,font=("Arial",32),borderwidth=4,relief="sunken",width=2)
label.grid(row = y,column = x,padx = 10,pady = 10)
label.bind("<Button-1>", lambda event:choose_space(label,x,y)) #adds label when space is clicked
Labels[x+3*y]=label #converts to coordinates of board as shown on top


def winner(new_board):# see if new board equals any winning combination
i=0
while i<len(wins):
win=wins[i]
if(new_board[win[0]]==new_board[win[1]] and new_board[win[1]]==new_board[win[2]] and new_board[win[0]]!=" "):
return new_board[win[0]]
i+=1
return ""

def open_spaces(board):#creates list of all open spaces on board for reference
ret=[]
for i in range(0,len(board)):
if board[i]==" ":
ret.append(i)
return ret

def change(player):
if player=="X":
return "O"
else:
return "X"

def minimax(board,player):
if winner(board)==computer:
return {"value":1,"position":-1}
if winner(board)==user:
return {"value":-1,"position":-1} #CHECK THIS LINE TO CHANGE ALGORITHM
spaces=open_spaces(board)
if len(spaces)<1:
return {"value":0,"position":-1} #tie
scores=[]
for i in range(0,len(spaces)):
next_move=spaces[i]
board[next_move]=player
score=minimax(board,change(player))
scores.append({"value":score["value"],"position":next_move})
board[next_move]=" "
if player==computer:
f=max
else:
f=min
best_move=f(scores, key=lambda x:x["value"])
return best_move




def next_turn(): #switches to next turn after each click on a space
global turn #works with global variable
if turn=='O':
turn='X'
else:
turn='O'

def choose_space(label,x,y):
if label['text']=="" and winner(board)=="":
label['text']=turn
board[x+3*y]=turn
if winner(board)!="":
showinfo("Winner","Player "+winner(board)+" has won")
next_turn()
if turn==computer:
best_move=minimax(board,computer)
position=best_move["position"]
if board[position]==" ": #if there is not a tie and game is not over
choose_space(Labels[position],position%3,position/3)


def addLabel(frame,text,x,y): #creates the labels for X and 0
label = Label(frame,text=text,font=("Arial",32),borderwidth=4,relief="sunken",width=2)
label.grid(row = y,column = x,padx = 10,pady = 10)
label.bind("<Button-1>", lambda event:choose_space(label,x,y)) #adds label when space is clicked
Labels[x+3*y]=label #converts to coordinates of board as shown on top

window=Tk()
window.title("Tic Tac Toe")
frame=Frame(window,width=400,height=400)

def start_program():
for x in range(0,3): #creates a board of blank spaces to start with
for y in range(0,3):
addLabel(frame,"",x,y)
global board
board=[" "]*9
global turn
turn="X"
frame.pack()

start_program()

Button(window, text="Restart", command=start_program).pack()

frame.pack()
frame.mainloop()