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TicTacToe and Minimax

I am a young programmer that is learning python and struggling to implement an AI (using minimax) to play TicTacToe. I started watching a tutorial online, but the tutorial was on JavaScript and thus couldn't solve my problem. I also had a look at this question ( Python minimax for tictactoe ), but it did not have any answers and the implementation was considerably different from mine.
EDIT: the code you will find below is an edit suggested by one of the answers (#water_ghosts).
EDIT #2: I deleted possiblePositions, as the AI should choose a free field and not a place from the possiblePositions (that wouldn't make it that smart while implementing minimax :) )
Now the code doesn't give out any errors at all and functions properly, but one small thing: the AI always chooses the next available field. For example in situations where i am i move away from winning, instead of blocking my win option, it chooses the next free spot.
If you're wondering what that elements dict is doing there: i just wanted to make sure the programm chose the best index...
Here is my code:
class TicTacToe:
def __init__(self):
self.board = [" ", " ", " ", " ", " ", " ", " ", " ", " "]
self.playerSymbol = ""
self.playerPosition = []
self.aiSymbol = ""
self.aiPosition = []
self.score = 0
self.winner = None
self.scoreBoard = {
self.playerSymbol: -1,
self.aiSymbol: 1,
"tie": 0
}
self.turn = 0
self.optimalMove = int()
def drawBoard(self):
print(self.board[0] + " | " + self.board[1] + " | " + self.board[2])
print("___" + "___" + "___")
print(self.board[3] + " | " + self.board[4] + " | " + self.board[5])
print("___" + "___" + "___")
print(self.board[6] + " | " + self.board[7] + " | " + self.board[8])
def choice(self):
answer = input("What do you want to play as? (type x or o) ")
if answer.upper() == "X":
self.playerSymbol = "X"
self.aiSymbol = "O"
else:
self.playerSymbol = "O"
self.aiSymbol = "X"
def won(self):
winningPositions = [{0, 1, 2}, {3, 4, 5}, {6, 7, 8}, {0, 4, 8}, {2, 4, 6}, {0, 3, 6}, {1, 4, 7}, {2, 5, 8}]
for position in winningPositions:
if position.issubset(self.playerPosition):
self.winner = self.playerSymbol
print("Player Wins :)")
return True
elif position.issubset(self.aiPosition):
self.winner = self.aiSymbol
print("AI wins :(")
return True
if self.board.count(" ") == 0:
self.winner = "tie"
print("Guess it's a draw")
return True
return False
def findOptimalPosition(self):
bestScore = float("-Infinity")
elements = {} # desperate times call for desperate measures
for i in range(9):
if self.board[i] == " ":
self.board[i] = self.aiSymbol # AI quasi made the move here
if self.minimax(True) > bestScore:
bestScore = self.score
elements[i] = bestScore
self.board[i] = " "
return max(elements, key=lambda k: elements[k])
def minimax(self, isMaximizing):
if self.winner is not None:
return self.scoreBoard[self.winner]
if isMaximizing:
bestScore = float("-Infinity")
for i in range(9):
if self.board[i] == " ":
self.board[i] = self.aiSymbol
bestScore = max(self.minimax(False), bestScore)
self.board[i] = " "
return bestScore
else:
bestScore = float("Infinity")
for i in range(9):
if self.board[i] == " ":
self.board[i] = self.playerSymbol
bestScore = min(self.minimax(True), bestScore)
self.board[i] = " "
return bestScore
def play(self):
self.choice()
while not self.won():
if self.turn % 2 == 0:
pos = int(input("Where would you like to play? (0-8) "))
self.playerPosition.append(pos)
self.board[pos] = self.playerSymbol
self.turn += 1
self.drawBoard()
else:
aiTurn = self.findOptimalPosition()
self.aiPosition.append(aiTurn)
self.board[aiTurn] = self.aiSymbol
self.turn += 1
print("\n")
print("\n")
self.drawBoard()
else:
print("Thanks for playing :)")
tictactoe = TicTacToe()
tictactoe.play()
I come from a java background and am not used to this :(
Any help would be highly appreciated
I am open to suggestions and ways to improve my code and fix this problem.
Thanks in advance and stay healthy,
Kristi

Change this part, your implementation will return optimalMove even if it doesn't go inside the if statement, and optimalMove will not be assigned at that point, so put the return inside.
if score > sampleScore:
sampleScore = score
optimalMove = i
return optimalMove

optimalMove = 0 in play() and optimalMove = i in findOptimalField() are declaring two distinct variables, each of which is local to the function declaring it.
If you want multiple functions to have access to the same variable, you can use the global keyword, but that's generally considered a bad practice. It can make it hard to reason about the code (e.g. is var = x creating a new local variable or overwriting the value of a global?) and it doesn't stop you from accidentally using a variable before it's declared.
Since you're coming from a Java background, you can turn this into a class to get behavior more like what you expect, eliminating the need for globals:
class TicTacToe:
def __init__(self):
self.board = [" ", " ", " ", " ", " ", " ", " ", " ", " "]
self.playerSymbol = ""
self.playerPosition = []
self.aiSymbol = ""
self.aiPosition = []
self.score = 0
self.playerSymbol = None
self.aiSymbol = None
...
def drawBoard(self):
print(self.board[0] + " | " + self.board[1] + " | " + self.board[2])
...
def choice(self):
answer = input("What do you want to play as? (type x or o) ")
if answer.upper() == "X":
self.playerSymbol = "X"
self.aiSymbol = "O"
...
Each method now takes an explicit self argument that refers to the current instance, and you can use this to access any variables that belong to the class instance instead of a particular method. If you don't include self. before a variable, that variable will still be local to the method that declares it. In this case, the drawBoard() method won't be able to access the answer variable defined in choice().
You can create new self. variables in any of the class's methods, but the best practice is to initialize all of them in the __init__ constructor method, using None as a placeholder for variables that don't have a value yet.

I am posting this as an answer, just in case somebody in the future stumbles upon the same problem :)
the main issue i encountered (besides my bad programming style) is that i forgot to update the contents the lists playerPosition and aiPosition.
You can review the rest of the changes in the working code:
class TicTacToe:
def __init__(self):
self.board = [" ", " ", " ", " ", " ", " ", " ", " ", " "]
self.playerSymbol = ""
self.playerPosition = []
self.aiSymbol = ""
self.aiPosition = []
self.winner = None
self.scoreBoard = None
self.turn = 0
self.optimalMove = int()
def drawBoard(self):
print(self.board[0] + " | " + self.board[1] + " | " + self.board[2])
print("___" + "___" + "___")
print(self.board[3] + " | " + self.board[4] + " | " + self.board[5])
print("___" + "___" + "___")
print(self.board[6] + " | " + self.board[7] + " | " + self.board[8])
def choice(self):
answer = input("What do you want to play as? (type x or o) ")
if answer.upper() == "X":
self.playerSymbol = "X"
self.aiSymbol = "O"
else:
self.playerSymbol = "O"
self.aiSymbol = "X"
self.scoreBoard = {
self.playerSymbol: -1,
self.aiSymbol: 1,
"tie": 0
}
def availableMoves(self):
moves = []
for i in range(0, len(self.board)):
if self.board[i] == " ":
moves.append(i)
return moves
def won_print(self):
self.won()
if self.winner == self.aiSymbol:
print("AI wins :(")
exit(0)
elif self.winner == self.playerSymbol:
print("Player Wins :)")
exit(0)
elif self.winner == "tie":
print("Guess it's a draw")
exit(0)
def won(self):
winningPositions = [{0, 1, 2}, {3, 4, 5}, {6, 7, 8},
{0, 4, 8}, {2, 4, 6}, {0, 3, 6},
{1, 4, 7}, {2, 5, 8}]
for position in winningPositions:
if position.issubset(self.playerPosition):
self.winner = self.playerSymbol
return True
elif position.issubset(self.aiPosition):
self.winner = self.aiSymbol
return True
if self.board.count(" ") == 0:
self.winner = "tie"
return True
self.winner = None
return False
def set_i_ai(self, i):
self.aiPosition.append(i)
self.board[i] = self.aiSymbol
def set_clear_for_ai(self, i):
self.aiPosition.remove(i)
self.board[i] = " "
def set_i_player(self, i):
self.playerPosition.append(i)
self.board[i] = self.playerSymbol
def set_clear_for_player(self, i):
self.playerPosition.remove(i)
self.board[i] = " "
def findOptimalPosition(self):
bestScore = float("-Infinity")
elements = {} # desperate times call for desperate measures
for i in self.availableMoves():
self.set_i_ai(i)
score = self.minimax(False)
if score > bestScore:
bestScore = score
elements[i] = bestScore
self.set_clear_for_ai(i)
if bestScore == 1:
print("you messed up larry")
elif bestScore == 0:
print("hm")
else:
print("whoops i made a prog. error")
return max(elements, key=lambda k: elements[k])
def minimax(self, isMaximizing):
if self.won():
return self.scoreBoard[self.winner]
if isMaximizing:
bestScore = float("-Infinity")
for i in self.availableMoves():
self.set_i_ai(i)
bestScore = max(self.minimax(False), bestScore)
self.set_clear_for_ai(i)
return bestScore
else:
bestScore = float("Infinity")
for i in self.availableMoves():
self.set_i_player(i)
bestScore = min(self.minimax(True), bestScore)
self.set_clear_for_player(i)
return bestScore
def play(self):
self.choice()
while not self.won_print():
if self.turn % 2 == 0:
pos = int(input("Where would you like to play? (0-8) "))
self.playerPosition.append(pos)
self.board[pos] = self.playerSymbol
self.turn += 1
self.drawBoard()
else:
aiTurn = self.findOptimalPosition()
self.aiPosition.append(aiTurn)
self.board[aiTurn] = self.aiSymbol
self.turn += 1
print("\n")
print("\n")
self.drawBoard()
else:
print("Thanks for playing :)")
if __name__ == '__main__':
tictactoe = TicTacToe()
tictactoe.play()
But as mentioned, the code may work, but there are MANY problems regarding the logic and structure, so do not straight-forward copy-paste it :))

Game getting stuck

I'm following a Python course on Udemy.com and we are practicing Python by building an RPG game. So far the game was working fine for a single player but as soon as we added 3 players the game seems to just get stuck after executing all 3 players attacks.
The concept is that there are 3 players or so, as the game starts the player stats are shown, after all the players have attacked each other this includes the enemy as well, the player stats are printed as shown below in the picture and the game asks for input from all the three players again, but it's just running once as shown below in the picture.
I followed the code for word to word and also posted a question regarding it. So I thought I should try StackoverFlow.
Below is my code kindly see why is it not going in loop as it should.
Mainfile
# -*- coding: utf-8 -*-
from game_class.invin import Item
from game_class.game import player
from game_class.magic import Spell
import time
# Player and Enemies magic create
Fire_Shot = Spell('Fire Shot', 10, 45, "Black Magic")
Thunder_Storm = Spell("Thunder Storm",25,65,"Black Magic")
Ninja_Summon = Spell("Ninja Summon",45,75,"Ninjustu")
The_End = Spell("THE END",80,300,"Finisher")
Heal = Spell("HEAL ME",60,140,'Heal')
player_magic = [Fire_Shot,Thunder_Storm,Ninja_Summon,Heal,The_End]
enemy_magic = [
{'Name': "Big Punch", 'cost': 30, "DMG": 45},
{'Name': "Slap", 'cost': 15, "DMG": 25},
{'Name': "Rock Throw", 'cost': 20, "DMG": 30},
{'Name': "Kick", 'cost': 45, "DMG": 60}
]
boss_magic = [
{'Name': "STORM", 'cost': 10, "DMG": 45},
{'Name': "DARK BACK-BITTING", 'cost': 10, "DMG": 25},
{'Name': "D.D.T", 'cost': 10, "DMG": 30}
]
# Items create
potion = Item("Potion", 'Potion', 'Heals for 50 HP', 50)
high_potion = Item("Potion+", 'Potion', 'Heals for 120 HP', 120)
super_potion = Item("Ultra Potion", 'Potion', 'Heal for 250 HP', 250)
elixir = Item("Elixir", 'Elixir', 'Give 1 EVERYTHING BACK', 9000)
high_elixir = Item("Omega Elixir", 'Elixir', 'Give all EVERYTHING BACK', 9000)
bomb = Item("Bomb",'Attack','Deals 350 Damage',350)
player_items = [ {"item":potion,"quantity":3},
{'item':high_potion,"quantity":2}
,{"item":super_potion,"quantity":1}
,{'item':elixir,"quantity":2}
,{'item':high_elixir,"quantity":1}
,{"item": bomb, "quantity": 2} ]
# PLAYER CREATE
Player1 = player('Night Man ',1000, 100, 145, 140, player_magic, player_items)
Player2 = player('Ray Wills ', 1000, 100, 155, 135, player_magic, player_items)
Player3 = player("Randy Orton",1000, 100, 150, 120, player_magic, player_items)
Enemy1 = player("Door Keeper",1500, 200, 250, 150, enemy_magic, None)
BOSS = player("Boss Man",1200, 200, 45, 300, boss_magic, None)
players = [Player1,Player2,Player3]
# Game starts
run = True
i = 1
while run is True:
print ("=======================================")
print("\n\n")
print(" NAME HP MP\n")
for player in players:
player.get_stats()
for player in players:
print("\n")
player.chose_action()
print("=========\n")
print (player.name)
print ("=============")
choice = input("CHOSE ACTION: ")
index = int(choice) - 1
if index == 0:
dmg = player.gen_dmg()
Enemy1.get_dmg(dmg)
print(player.name+ " attacked for " + str(dmg) + " damage points")
elif index == 1:
player.chose_magic()
magic_choice = (int(input("Chose Spell: ")) - 1)
spell = player.magic[magic_choice]
magic_dmg = spell.gen_spell_dmg()
current_mp = player.get_mp()
if magic_choice == -1:
continue
if spell.cost > current_mp:
print ("\nNOT ENOUGH MANA")
continue
if spell.stype == "Heal":
player.heal(magic_dmg)
print (str(magic_dmg) +' HP restored')
print("Remaining Magic Points: " + str(player.get_mp()) +
"/" + str(player.get_max_mp()))
elif spell.stype == "Black Magic" or spell.stype == "Ninjustu" or spell.stype == "Finisher":
player.reduce_mp(spell.cost)
Enemy1.get_dmg(magic_dmg)
print (str(spell.name) + ' did damage of '+ str(magic_dmg) +" points")
print ("Remaining Magic Points: " + str(player.get_mp()) +"/" +str(player.get_max_mp()))
elif index == 2:
player.chose_item()
item_choice = (int(input("Chose Spell: ")) - 1)
if item_choice == -1:
continue
item = player.items[item_choice]['item']
if player.items[item_choice]['quantity'] == 0:
print("No Item...")
continue
player.items[item_choice]['quantity'] -= 1
if item.itype == 'Potion':
player.heal(item.prop)
print("\n"+ str(item.name) + " used and healed for "+ str(item.prop) + " HP")
elif item.itype == "Elixir":
player.hp = Player1.maxhp
player.mp = Player1.maxmp
print ("\n"+"STATS RESTORED BECASUE OF " +str(item.name))
elif item.itype == "Attack":
Enemy1.get_dmg(item.prop)
print ("You used a Bomb & that dealt damage of: " + str(item.prop))
enemy_choice = 1
enemy_dmg = Enemy1.gen_dmg()
Player1.get_dmg(enemy_dmg)
print("========================================")
print("\n")
print ("ENEMY ATTACKED YOU FOR " + str(enemy_dmg) + " POINTS")
print ("ENEMY HP: "+str(Enemy1.get_hp()) +'/'+ str(Enemy1.get_maxhp()))
if Enemy1.get_hp() == 0:
print('')
print ('ENEMY DEAD')
run = False
elif Player1.get_hp() == 0:
print('')
print('YOU DIED')
run = False
elif index == 3:
print("Arigato Gozaimasu for playing")
time.sleep(1)
print ("BYE BYE")
run = False
invin.py
class Item:
def __init__(self, name,itype,desc,prop):
self.name = name
self.itype = itype
self.desc = desc
self.prop = prop
magic.py
import random
class Spell():
def __init__(self, name, cost,dmg,stype):
self.name = name
self.cost = cost
self.dmg = dmg
self.stype = stype
def gen_spell_dmg(self):
low = self.dmg - 15
high = self.dmg + 10
return random.randrange(low,high)
game.py
# -*- coding: utf-8 -*-
from .magic import Spell
import random
class player:
def __init__(self,name, hp , mp , atk ,df ,magic,items):
self.hp = hp
self.name = name
self.items = items
self.mp = mp
self.magic = magic
self.df = df
self.maxhp = hp
self.atkH = atk + 25
self.atkL= atk - 10
self.actions=['Attack',"Magic","Items"]
self.maxmp = mp + 10
def gen_dmg(self):
return random.randrange(self.atkL,self.atkH)
def get_dmg(self,dmg):
self.hp -= dmg
if self.hp < 0:
self.hp = 0
return self.hp
def get_hp(self):
return self.hp
def get_maxhp(self):
return self.maxhp
def get_max_mp(self):
return self.maxmp
def get_mp(self):
return self.mp
def reduce_mp(self,cost):
self.mp -= cost
def spell_cost(self, i):
return self.magic[i]["cost"]
def chose_action(self):
print ("Actions")
print ("===========")
i = 1
for item in self.actions:
print(" " + str(i)+":" + str(item))
i += 1
def chose_magic(self):
print ("Spells")
print ("===========")
i = 1
for spell in self.magic:
print (" " + str(i) + ": " + str(spell.name) + str( " (Cost: " + str ( spell.cost ) +")" ) )
#the 3rd str helps to print it without the brackets
i += 1
def chose_item(self):
print ("Items")
print ("===========")
i = 1
for item in self.items:
print(" " + str(i) + ": " +
str(item['item'].name) + str(" (" + str(item['item'].desc) + ") ") + " (x"+str(item['quantity'])+")")
#the 3rd str helps to print it without the brackets
i += 1
def heal(self,dmg):
self.hp += dmg
def get_stats(self):
hp_bar = ''
bar_ticks = ( (self.hp/self.maxhp) * 100 ) / 4
mp_bar = ''
mp_bar_ticks = ( (self.mp/self.maxmp) * 100 ) / 10
while bar_ticks > 0:
hp_bar += '█'
bar_ticks -= 1
while len(hp_bar) < 25:
hp_bar = " "
while mp_bar_ticks > 0:
mp_bar += '▒'
mp_bar_ticks -= 1
while len(mp_bar) < 10:
mp_bar = " "
hp_string = str(self.hp) + "/"+str(self.maxhp)
current_hp = ''
if len(hp_string) < 9:
decreased = 9 - len(hp_string)
while decreased > 0:
current_hp += ' '
decreased -= 1
current_hp += hp_string
else:
current_hp = hp_string
mp_string = str(self.mp) +"/"+str(self.maxmp)
current_mp = ''
if len(mp_string) < 9:
mp_decreased = 9 - len(mp_string)
while mp_decreased > 0:
current_mp += ' '
mp_decreased -= 1
current_mp += mp_string
else:
current_mp = mp_string
print(" _________________________ __________")
print(str(self.name) + " " + str(hp_string) +
" |"+ hp_bar+"| " + str(mp_string) + " |"+mp_bar+"|")
The game is an RPG replica and it works by using while loop.
Each player gets a turn and then the player stats are shown after all 3 players have attacked.
This is how the loop should show player stats after all 3 players attacked
But I'm getting this

If we compare the "This is how the loop should show player stats after all 3 players attacked" and "But I'm getting this" screenshots, we can see, by looking at the code, that the issue is caused on the second run of player.get_stats(). This method is defined in the game.py file.
Inside the method we can see the following 2 lines of code:
while len(hp_bar) < 25:
hp_bar = " "
If the while-loop ever gets to run, it will be stuck forever. This is because if len(hp_bar) < 25 is True, the code does hp_bar = " ", which in turns makes len(hp_bar) to be equal to 1 now. This now gets the while loop to check if len(hp_bar) < 25 again, which returns True (as len(hp_bar) is 1) so the while-loop runs again. This creates an endless loop.

Python: Create Dict in function a and call it in function b

i have a problem with creating a dict in python.
In my mainloop i call function 1 which should creat an empty dict.
function 1 calls function 2.
function 2 calls itself (loop through a game tree)
but i can not use the dict i created in f1.
and it is not possible to pass it as agrument.
i would like to have the dict globaly accessible
def f1(): # function 1
#test_dict = {} # this needs to be global scope
#test_dict["key"] = "value"
test_dict["key2"] = "value2"
print (test_dict)
f2()
def f2(): # function 2
# here starts a loop that calls f2 again and again -> global dict is needed
# dict needs to be created
print (test_dict)
test_dict = {} # only works without errors when i create it before calling f1
test_dict["key"] = "value"
f1()
Here is my "real" Code :)
The >>MinMaxComputerMove<< need to edit the dict.
but at the end of a nood i cant pass it because the for loop just goes on.
# [] [] []
# [] [] []
# [] [] []
#Input Layer:
#9 Punkte mit -1 (geg.) 0 (leer) 1 (eig.)
from time import sleep
from random import randint
from random import choice
from IPython.display import clear_output
def clearBoard():
board = [0] * 10
return (board)
def drawBoard(board, PlayerSymbol, ComputerSymbol, turn):
turn += 1
#clear_output()
Symbolboard = []
for index, value in enumerate(board):
if value == 1:
Symbolboard.append(PlayerSymbol)
elif value == -1:
Symbolboard.append(ComputerSymbol)
else:
Symbolboard.append(" ")
print ("Turn: " + str(turn))
print ("")
print (str(Symbolboard[7]) + " - " + str(Symbolboard[8]) + " - " + str(Symbolboard[9]))
print ("| \ | / |")
print (str(Symbolboard[4]) + " - " + str(Symbolboard[5]) + " - " + str(Symbolboard[6]))
print ("| / | \ |")
print (str(Symbolboard[1]) + " - " + str(Symbolboard[2]) + " - " + str(Symbolboard[3]))
return (validMoves(board), turn)
def validMoves(board):
#return list with valid indices
validMoveList = []
for index, value in enumerate(board):
if index > 0 and value == 0:
validMoveList.append(index)
return (validMoveList)
def Symbol():
#X always goes first
if randint(0, 1) == 0:
print ("X: YOU")
print ("O: COMPUTER")
return ("X"), ("O")
else:
print ("X: COMPUTER")
print ("O: YOU")
return ("O"), ("X")
def PlayerMove(validMoveList, PlayerSymbol):
PlayerInput = input("Welches Feld? (1-9):")
if int(PlayerInput) in validMoveList:
return (PlayerInput, PlayerSymbol)
else:
print("Falsche Eingabe." + PlayerInput + " kein möglicher Zug")
def ComputerMove(validMoveList, board, PlayerSymbol, ComputerSymbol, AI):
print("ComputerMove")
if AI == 1:
return RandomComputerMove(validMoveList, ComputerSymbol)
elif AI == 2:
path_dict = {}
return MinMaxComputerMove(validMoveList, board, PlayerSymbol, ComputerSymbol, depth = 1, firstrun = 1)
# more AIs
# ...
def ComputerThinking():
print("Computer is thinking", end = "")
sleep(0.5)
print(".", end = "")
sleep(0.5)
print(".", end = "")
sleep(0.5)
print(".")
sleep(1)
return
def RandomComputerMove(validMoveList, ComputerSymbol):
ComputerChoice = choice(validMoveList)
ComputerThinking()
print("ComputerChoice: " + str(ComputerChoice))
sleep(1.5)
print("RandomComputerMove Output: " + str((ComputerChoice, ComputerSymbol)))
return (ComputerChoice, ComputerSymbol)
def MinMaxComputerMove(validMoveList, board, PlayerSymbol, ComputerSymbol, depth, firstrun = 0, start_path = -1):
initial_validMoveList = validMoveList.copy()
initial_board = board.copy()
turns_left = len(initial_validMoveList)
#debug
print("firstrun: " + str(firstrun))
print("depth: " + str(depth))
if firstrun == 1: #first run of function
path_dict = {}
for path, field in enumerate(initial_validMoveList):
path_dict[path] = {}
for extent in range(3):
path_dict[path][extent+1] = 5
#debug
print("---MinMaxComputerMove---")
print("Start MinMaxComputerMove with depth: " + str(depth))
print("validMoveList: " + str(validMoveList) + str(id(validMoveList)))
print("board: " + str(board) + str(id(board)))
print("ComputerSymbol: " + str(ComputerSymbol))
print("start_path: " + str(start_path))
for path, field in enumerate(initial_validMoveList): #(2, 6, 8):
if firstrun == 1:
start_path = path
print("start_path: " + str(start_path))
# for every path in tree diagram create a key in dict with empty list
# goal: dict("path": [field, depth_1_(max)value, depth_2_(min)value, depth_3_(max)value])
#debug
print("depth: " + str(depth))
if depth % 2 == 1: # Computer:
ChoosenIndex = (str(field), ComputerSymbol)
else: # Player
ChoosenIndex = (str(field), PlayerSymbol)
new_board = updateBoard(initial_board.copy(), ChoosenIndex, PlayerSymbol) # copy() or initial_board would change
new_validMoveList = validMoves(new_board)
#debug
print("---For Loop---")
print("ChoosenIndex: " + str(ChoosenIndex) + str(id(ChoosenIndex)))
print("new_validMoveList: " + str(new_validMoveList) + str(id(new_validMoveList)))
print("new_board: " + str(new_board) + str(id(new_board)))
print("path_dict: " + str(path_dict))
print("depth: " + str(depth))
if checkWinner(new_board) == 0 and depth != 3 and turns_left >= 1: # no winner yet and game not over
print ("no winner yet and game not over")
# go deeper
path_dict[start_path][depth] = 0
MinMaxComputerMove(new_validMoveList, new_board, PlayerSymbol, ComputerSymbol, depth + 1, 0, start_path)
elif checkWinner(new_board) == 0 and depth == 3 and turns_left >= 1: # no winner yet and game not over and minmax ends (depth = 3)
print ("checkWinner(new_board) == 0 and depth == 3 and turns_left >= 1")
path_dict[start_path][depth] = 0
elif checkWinner(new_board) == -1: # computer wins
print ("elif checkWinner(new_board) == -1")
if depth % 2 == 1: # Computer -> MIN:
path_dict[start_path][depth] <= -1
else: # Player -> MAX
if path_dict[start_path][depth] > -1:
path_dict[start_path][depth] = -1
elif checkWinner(new_board) == 1: # player wins
print ("elif checkWinner(new_board) == 1")
path_dict[start_path][depth] = 1
elif depth >= 3 or turns_left < 1: # reached depth 3 or no more turns
print ("elif depth >= 3 or turns_left < 1:")
else:
print ("else")
print("--- END FOR PATH ---")
print("--- END FOR LOOP ---")
print(path_dict)
# return choise
return (2, ComputerSymbol)
def updateBoard(board, ChoosenIndex, PlayerSymbol): #[0, 1, -1, 0, ...],[5, "X"], "X"
if PlayerSymbol == ChoosenIndex[1]:
board[int(ChoosenIndex[0])] = 1
return (board)
else:
board[int(ChoosenIndex[0])] = -1
return (board)
def checkWinner(board):
if (board[7] == board[8] == board[9]) and 0 != board[7]: # top row
return board[7]
elif (board[4] == board[5] == board[6]) and 0 != board[4]: # mid row
return board[4]
elif (board[1] == board[2] == board[3]) and 0 != board[1]: # bot row
return board[1]
elif (board[7] == board[4] == board[1]) and 0 != board[7]: # left column
return board[7]
elif (board[8] == board[5] == board[2]) and 0 != board[8]: # mid row
return board[8]
elif (board[9] == board[6] == board[3]) and 0 != board[9]: # right row
return board[9]
elif (board[7] == board[5] == board[3]) and 0 != board[7]: # diagonal \
return board[7]
elif(board[1] == board[5] == board[9]) and 0 != board[1]: # diagonal /
return board[1]
else:
return 0
def GameLoop(AI, turn = 0, winner = 0):
#choose AI difficulty
#...
#...
#set first player (X)
PlayerSymbol, ComputerSymbol = Symbol()
sleep(3)
#init board with list 10 * 0
board = clearBoard()
#debug
board = [0, 1, 0, 1, -1, -1, 0, 1, 0, -1]
PlayerSymbol, ComputerSymbol = ("O", "X") # computer first
#draw current board
validMoveList, turn = drawBoard(board, PlayerSymbol, ComputerSymbol, turn)
while winner == 0 and turn <=9:
sleep(1.5)
if turn % 2 == 1: # "X" player move
if PlayerSymbol == "X":
#player move
ChoosenIndex = PlayerMove(validMoveList, PlayerSymbol)
#update current board
board = updateBoard(board, ChoosenIndex, PlayerSymbol)
#draw current board
validMoveList, turn = drawBoard(board, PlayerSymbol, ComputerSymbol, turn)
#check for winner
winner = checkWinner(board)
else:
#computer move
ChoosenIndex = ComputerMove(validMoveList, board, PlayerSymbol, ComputerSymbol, AI)
#update current board
board = updateBoard(board,ChoosenIndex, PlayerSymbol)
#draw current board
validMoveList, turn = drawBoard(board, PlayerSymbol, ComputerSymbol, turn)
#check for winner
winner = checkWinner(board)
else: # "O" player move
if PlayerSymbol == "O":
#player move
ChoosenIndex = PlayerMove(validMoveList, PlayerSymbol)
#update current board
board = updateBoard(board,ChoosenIndex, PlayerSymbol)
#draw current board
validMoveList, turn = drawBoard(board, PlayerSymbol, ComputerSymbol, turn)
#check for winner
winner = checkWinner(board)
else:
#computer move
ChoosenIndex = ComputerMove(validMoveList, board, PlayerSymbol, ComputerSymbol, AI)
#update current board
board = updateBoard(board,ChoosenIndex, PlayerSymbol)
#draw current board
validMoveList, turn = drawBoard(board, PlayerSymbol, ComputerSymbol, turn)
#check for winner
winner = checkWinner(board)
else:
if winner == 1:
print ("YOU WON!")
elif winner == -1:
print ("COMPUTER WON!")
else:
print ("DRAW!")
GameLoop(AI = 2)

The "return value" answer is:
def f1(test_dict): # function 1
#test_dict = {} # this needs to be global scope
#test_dict["key"] = "value"
test_dict["key2"] = "value2"
print ('In f1 {}'.format(test_dict))
f2(test_dict)
return test_dict
def f2(test_dict): # function 2
# here starts a loop that calls f2 again and again -> global dict is needed
# dict needs to be created
print ('In f2 {}'.format(test_dict))
return test_dict
test_dict = {} # only works without errors when i create it before calling f1
test_dict["key"] = "value"
test_dict = f1(test_dict)
which gives output of:
In f1 {'key2': 'value2', 'key': 'value'}
In f2 {'key2': 'value2', 'key': 'value'}
But at some level, you probably want to put some of this into a class and then have test_dict as a variable within the class. That allows f1 and f2 (assuming they are class methods) to access the class variable without passing it as a parameter to the two methods.
class Example:
def __init__(self):
self._test_dict = {}
self._test_dict["key"] = "value"
def f1(self): # function 1
self._test_dict["key2"] = "value2"
print ('In f1 {}'.format(self._test_dict))
self.f2()
def f2(self): # function 2
print ('In f2 {}'.format(self._test_dict))
example = Example()
example.f1()

Below is a very simply version of what your script is attempting. You need to consider what your function parameters should be (what is passed to the function), as well as what your function should be providing at the end of its execution (given to you with the return statement). This way you can manipulate objects without having to keep everything in global scope, and you can avoid having to initialize every conceivable variable at the start of the routine.
Python Functions
Return Statement
def f1():
f1_dict = {}
f1_dict = f2(f1_dict)
return f1_dict
def f2(dict_arg):
f2_dict = {}
for i in range(0,5):
f2_dict[str(i)] = i**i
return f2_dict
dictionary = f1()
print(dictionary)

Python Class Setters Not Changing Variables

The closest thread I could find to my problem was this: Python setter does not change variable
It didn't really help, the volume and the channels are not changing at all. The first fucntion which is to "watch TV" works perfectly fine.
class TV(object):
def __init__(self, channel, volume):
self.__channel = channel
self.__volume = volume
def __str__(self):
out = ""
out += "You're on channel #" + str(self.__channel) + ", " + self.channelNetwork()
out += "\nVolume is currently at: " + str(self.__volume) + "/20"
return out
# a method that determines the name for each channel from 1-10
def channelNetwork(self):
c = self.__channel
if c == 1:
return "CBS"
elif c==2:
return "NBC"
elif c==3:
return "ABC"
elif c==4:
return "Fox"
elif c==5:
return "ESPN"
elif c==6:
return "PBS"
elif c==7:
return "CNN"
elif c==8:
return "Comedy Central"
elif c==9:
return "Cartoon Network"
elif c==10:
return "Nicklodeon"
# a volume slider that has a range from 0-20
def volumeSlider(self, newVolume):
v = self.__volume
if newVolume == "+":
v += 1
else:
v -= 1
if v < 0:
v = 0
if v > 20:
v = 20
def channelChanger(self, newChannel):
c = self.__channel
if newChannel == "+":
c += 1
else:
c -= 1
if c < 0:
c = 0
if c > 10:
c = 10
def main():
import random
randomChannel = random.randint(1,10)
randomVolume = random.randrange(21)
televsion = TV(randomChannel, randomVolume)
choice = None
while choice != "0":
print \
("""
TV Simulator
0 - Turn off TV
1 - Watch TV
2 - Change channel
3 - Change volume
""")
choice = input("Choice: ")
print()
# exit
if choice == "0":
print("Have a good day! :)")
elif choice == "1":
print("You relax on your couch and watch some TV")
print(televsion)
elif choice == "2":
newChannel = None
while newChannel not in ('+', '-'):
newChannel = input("\nPress '+' to go up a channel and press '-' to go down a channel: ")
televsion.channelChanger(newChannel)
elif choice == "3":
newVolume = None
while newVolume not in ('+', '-'):
newVolume = input("\nPress '+' to increase volume and press '-' to decrease volume: ")
televsion.volumeSlider(newVolume)
else:
print("\nSorry, but", choice, "isn't a valid choice.")
main()
input("\n\nPress enter to exit.")

The problem is, that when you do:
v = self.__volume
In:
def volumeSlider(self, newVolume):
v = self.__volume
if newVolume == "+":
v += 1
else:
v -= 1
if v < 0:
v = 0
if v > 20:
v = 20
Assigning to v won't affect self.__volume. You need to use self.__volume = 20 or whatever.
As an aside, don't use double-underscore name-mangling unless you actually need it. E.g. self.volume is fine.

Recording a win or loss in a game of craps

So I have to create a game of craps that takes into account bets for an assignment. So far, my code works in that the dice rolls are correct and other little tidbits the assignment called for. But now I don't know how to record each game as a win / lose for the player or computer so that the pot can be added to the winner's money. I realize that my code is half doe, isn't finished, and doesn't run as is, but I just seriously need some help from someone. Please and thank you. Here are more specific directions on my assignment:
http://www.ics.uci.edu/~kay/courses/i42/hw/labA.html
import random
def craps():
print("Welcome to Sky Masterson's Craps Game")
handle_commands()
def handle_commands(): # Collection -> Collection (plus interaction)
""" Display menu to user, accept and process commands
"""
playerInitial = 500
compInitial = 500
MENU = "How much would you like to bet?: "
while True:
bet = float(input(MENU))
if bet <= playerInitial:
human_game()
elif bet > playerInitial:
print("Sorry, you can't bet more than you have")
def handle_commands2():
MENU2 = "Would you like to play again? (y or n): "
while True:
response = input (MENU2)
if response=="y":
counter = counter + multipleGames()
elif response=="n":
while ( counter < 2000):
roll = random.randint(1, 6) + random.randint(1,6)
updateCount(roll)
counter += 1
print ("Thank you for playing." + "\n" + "\n" + "Distribution of dice rolls: " + "\n")
return
else:
invalid_command(response)
def invalid_command(reponse):
"""print message for invalid menu command.
"""
print("Sorry; '" + response + "' isn't a valid command. Please try again.")
def play_game():
"""prints shooters roll results
"""
diceRoll = 0
roll = random.randint(1, 6) + random.randint(1, 6)
updateCount(roll)
diceRoll = diceRoll + 1
point = 0
print("The roll is " + str(roll))
response = (roll)
if response== 7 or response== 11:
print("Natural; shooter wins" + "\n" + "Thank you for playing")
handle_commands2()
elif response== 2 or response== 3 or response== 12:
print("Crapped out; shooter loses" + "\n" + "Thank you for playing")
handle_commands2()
else:
print("The point is " + str(roll))
point = roll
secondRoll = 0
handle_commands()
while (secondRoll !=point) and (secondRoll != 7):
secondRoll = random.randint(1, 6) + random.randint(1, 6)
updateCount(secondRoll)
diceRoll += 1
print("The roll is " + str(secondRoll))
handle_commands()
if secondRoll== point:
print ("Made the point; shooter wins." + "\n" + "Thank you for playing")
handle_commands2()
elif (secondRoll == 7):
print ("Crapped out; shooter loses." + "\n" + "Thank you for playing")
handle_commands2()
return diceRoll
def multipleGames():
gameCounter = 0
while (gameCounter <= 2000):
print("Your game: ")
gameCounter += play_game()
print("\n")
print("Computer's game: ")
gameCounter += play_game()
print( "\n")
return gameCounter
def updateCount(point):
count =List[point] + 1
List[point] = count
List = {2:0, 3:0, 4:0, 5:0, 6:0, 7:0, 8:0, 9:0, 10:0, 11:0, 12:0}
def human_game():
playerInitial = 500
compInitial = 500
while True:
play_game()
if
playerInitial += bet
compInitial += bet
counter = 0
counter = counter + multipleGames()
playerInitial -= bet
craps()
for point in List:
print("%2d" %(point) + ": " + "%3d" %(List[point]) + " " + "(" + ("%2d" % (int((List[point])/2000*100)))+ "%" + ")" + " " + ("*" *(int((List[point])/2000*100))))

Use classes:
import random
class Human:
def __init__(self):
self.name = 'Human'
self.wins = []
self.losses = []
self.bets = []
self.total = 0
class Computer:
def __init__(self):
self.name = 'Computer'
self.wins = []
self.losses = []
self.bets = []
self.total = 0
class Game:
def __init__(self):
self.rolls = []
self.currentPlayer = None
def roll(self):
self.rolls.append(random.randint(1, 6))
if __name__ == '__main__':
human = Human()
computer = Computer()
game = Game()
game.roll()
print games.rolls
I won't code all of it for you, but using classes will make things much simpler.