Python Tic Tac Toe using minimax does not make best move - python-3.x

Question

I have been trying to get this to work for over a week now and cant seem to get it to choose the best possible move. Can someone take a look and help me out? I feel like I have missed something stupid.
Thanks!
from tkinter import *
import tkinter.messagebox
tk = Tk()
tk.title("Tic Tac Toe")
click = True
X = "X"
O = "O"
EMPTY = " "
TIE = "TIE"
NUM_SQUARES = 9
def new_board():
"""Create new game board."""
board = []
for square in range(NUM_SQUARES):
board.append(EMPTY)
return board
def Player1Win(board, i):
if(board[0]==1 and board[1]==1 and board[2]==1)or(board[0]==1 and board[3]==1 and board[6]==1)or(board[2]==1 and board[5]==1 and board[8]==1)or(board[3]==1 and board[4]==1 and board[5]==1)or(board[6]==1 and board[7]==1 and board[8]==1)or(board[0]==1 and board[4]==1 and board[8]==1)or(board[2]==1 and board[4]==1 and board[6]==1)or(board[1]==1 and board[4]==1 and board[7]==1)or(board[0]==1 and board[3]==1 and board[6]==1):
if(i==0):
tkinter.messagebox.showinfo("Winner X won")
return True
else:
return False
def Player2Win(board, i):
if(board[0]==0 and board[1]==0 and board[2]==0)or(board[0]==0 and board[3]==0 and board[6]==0)or(board[2]==0 and board[5]==0 and board[8]==0)or(board[3]==0 and board[4]==0 and board[5]==0)or(board[6]==0 and board[7]==0 and board[8]==0)or(board[0]==0 and board[4]==0 and board[8]==0)or(board[2]==0 and board[4]==0 and board[6]==0)or(board[1]==0 and board[4]==0 and board[7]==0):
if(i==0):
tkinter.messagebox.showinfo("Winner O won")
return True
else:
return False
board2=new_board()
board=new_board()
def legal_moves(board):
"""Create list of legal moves."""
moves = []
count = 0
for square in range(NUM_SQUARES):
if board[square] == EMPTY:
count += 1
moves.append(square)
print(count)
return moves
def minimax(board2):
global click
#Get all possible steps
moves=legal_moves(board2)
#Check copy board to win
if(Player1Win(board2,2) == True):
return 10
if(Player2Win(board2,2) == True):
return -10
if(len(moves)==0):
return 0
j = 1000
for i in moves:
if click:
click=True #change to Player X
board2[i]=0 #This is a copy of the board is not the main
else:
click=False #to change Player O
board2[i]=1 #This is a copy of the board is not the main
v = minimax(board2) # Recursive call functions
# # Select the minimum number for O and maximum for X
if j == 1000 or (click == False and j < v) or (click == True and v < j):
j = v
if click:
return j-1 # If player O
else:
return j+1 # If player X
def bestMove():
global click
# Get all possible steps
moves=legal_moves(board)
# Move all the data from the main board
for k in range(NUM_SQUARES):
board2.append(board[k])
j = 1000
best = -1
for i in moves:
if click:
click = False #change to Player X
board2[i]=0
else:
click = True #change to Player O
board2[i]=1
v = minimax(board2)
# Select the minimum number for O and maximum for X
if j == 1000 or (click == False and j < v) or (click == True and v < j):
j = v
best = i
return best
def Update(board):
global click
if button1["text"]=="X":
board[0]=1
if button2["text"]=="X":
board[1]=1
if button3["text"]=="X":
board[2]=1
if button4["text"]=="X":
board[3]=1
if button5["text"]=="X":
board[4]=1
if button6["text"]=="X":
board[5]=1
if button7["text"]=="X":
board[6]=1
if button8["text"]=="X":
board[7]=1
if button9["text"]=="X":
board[8]=1
if button1["text"]=="O":
board[0]=0
if button2["text"]=="O":
board[1]=0
if button3["text"]=="O":
board[2]=0
if button4["text"]=="O":
board[3]=0
if button5["text"]=="O":
board[4]=0
if button6["text"]=="O":
board[5]=0
if button7["text"]=="O":
board[6]=0
if button8["text"]=="O":
board[7]=0
if button9["text"]=="O":
board[8]=0
def move(i):
global click
click = False
if i == 0:
button1["text"] = "O"
board[0]=0
elif i == 1:
button2["text"] = "O"
board[1]=0
elif i == 2:
button3["text"] = "O"
board[2]=0
elif i == 3:
button4["text"] = "O"
board[3]=0
elif i == 4:
button5["text"] = "O"
board[4]=0
elif i == 5:
button6["text"] = "O"
board[5]=0
elif i == 6:
button7["text"] = "O"
board[6]=0
elif i == 7:
button8["text"] = "O"
board[7]=0
elif i == 8:
button9["text"] = "O"
board[8]=0
def checker(buttons):
global click
if buttons["text"] == " ":
buttons["text"] = "X"
click = True
Update(board)
best = bestMove()
move(best)
Player1Win(board, 0)
Player2Win(board, 0)
buttons = StringVar()
button1 = Button(tk,text=" ",font=('Times 26 bold'), height = 4, width = 8, command =lambda:checker(button1))
button1.grid(row=1,column=0,sticky = S+N+E+W)
button2 = Button(tk,text=" ",font=('Times 26 bold'), height = 4, width = 8, command =lambda:checker(button2))
button2.grid(row=1,column=1,sticky = S+N+E+W)
button3 = Button(tk,text=" ",font=('Times 26 bold'), height = 4, width = 8, command =lambda:checker(button3))
button3.grid(row=1,column=2,sticky = S+N+E+W)
button4 = Button(tk,text=" ",font=('Times 26 bold'), height = 4, width = 8, command =lambda:checker(button4))
button4.grid(row=2,column=0,sticky = S+N+E+W)
button5 = Button(tk,text=" ",font=('Times 26 bold'), height = 4, width = 8, command =lambda:checker(button5))
button5.grid(row=2,column=1,sticky = S+N+E+W)
button6 = Button(tk,text=" ",font=('Times 26 bold'), height = 4, width = 8, command =lambda:checker(button6))
button6.grid(row=2,column=2,sticky = S+N+E+W)
button7 = Button(tk,text=" ",font=('Times 26 bold'), height = 4, width = 8, command =lambda:checker(button7))
button7.grid(row=3,column=0,sticky = S+N+E+W)
button8 = Button(tk,text=" ",font=('Times 26 bold'), height = 4, width = 8, command =lambda:checker(button8))
button8.grid(row=3,column=1,sticky = S+N+E+W)
button9 = Button(tk,text=" ",font=('Times 26 bold'), height = 4, width = 8, command =lambda:checker(button9))
button9.grid(row=3,column=2,sticky = S+N+E+W)
tk.mainloop()
print ("Please Begin Play")

Answer 1

I would suggest you add print statements to see what is happening. Start with printing "click" for each pass through the for() loop and also print what the return (j +- 1) and the value for "i" right before the return statements (and please don't use "i", "l", or "O" as single digit variable names as they can look like numbers, i.e, o=1, o=l). You can handle the really, really long and really, really, confusing line a lot better with a list of win combinations.
## a simple example that will require some modification by you
def check_for_winner(player, board):
## fill in the rest yourself
win_combos=[[0, 1, 2], [3, 4, 5], [6, 7, 8], [0, 4, 8], [0, 3, 6]]
for x, y, z in win_combos:
print "checking", x, y, z
if board[x] == board[y] == board[z]:
print "**** We have a winner", player, x, y, z
return True
return False