python appears to be overwriting variables by itself [duplicate] - python

This question already has answers here:
How do I pass a variable by reference?
(39 answers)
Closed 8 years ago.
As an attempt to pick up the basics of python I decided to try and recreate nim sticks in python 3. I'm using pyCharm for this development.
When the AI player checks for what sticks to remove the lines variable in the game_ai function appears to overwrite itself for no apparent reason.
main.py:
import ai
import helpers
lines = [1, 3, 5, 7]
winner = 0
# String introduction
print(' _____ _ _ _ ')
print(' / ____| | (_) | | ')
print(' | (___ | |_ _ ___| | _____ ')
print(' \___ \| __| |/ __| |/ / __| ')
print(' ____) | |_| | (__| <\__ \ ')
print(' |_____/ \__|_|\___|_|\_\___/ ')
print('The last one to pick up a stick loses!')
# Keep going till we have a winner!
while winner == 0:
# Redraw the stick board at the start of a turn
helpers.redraw_sticks(lines)
# Get user input and remove their sticks
line = helpers.check_input('Please select a line to remove (a) stick(s) from:', 0, 4, 'line', lines)
amount = helpers.check_input('Please select how many stick(s) you wish to remove:', 0, 7, 'amount', lines)
lines = helpers.remove_sticks(lines, line, amount)
# Check for winner
winner = helpers.winner_check(lines, 1)
# Only play the AI if the player doesn't win this go
if winner == 0:
# Redraw the board after a go
helpers.redraw_sticks(lines)
# Play the AI
ai_turn = ai.game_ai(lines)
lines = helpers.remove_sticks(lines, ai_turn[0], ai_turn[1] - 1)
# Check for winner
winner = helpers.winner_check(lines, 2)
# Declare the winner!
if winner == 1:
print('The Human Player wins the game!')
else:
print('The Computer Player wins the game!')
ai.py:
import helpers
import time
# Our cool kid AI
def game_ai(lines):
winning_data = [0, 0]
winning_combo = False
# Keep going till we get a winning nim sum
while not winning_combo:
line = 1
# Go through every line
while line <= 4 and not winning_combo:
# Reset amount value
amount = 7
# Make it look like there's actual heavy processing going on here
print('AI player is thinking...')
time.sleep(1)
# Only go if the line actually has sticks
if lines[line - 1] != 0:
# Test certain values in a line
while amount >= 1 and not winning_combo:
lines_test = helpers.remove_sticks(lines, line, amount)
# If we have a nim sum of 0 we go!
if helpers.nim_sum(lines_test) == 0:
winning_combo = True
winning_data[0] = line
winning_data[1] = amount
# I'm going to win, I shouldn't do this...
if helpers.lines_checksum(lines_test) == 0:
winning_data[1] = amount - 1
# Increment amount
amount -= 1
# Increment line
line += 1
# Return winning data
return winning_data
helpers.py:
import sys
# Redraws the stick board with updated values
def redraw_sticks(lines):
# Loop through each line
for (line, sticks) in enumerate(lines):
if sticks > 0:
# Output line number
sys.stdout.write(str(line + 1) + ': ')
# And output how many sticks there are
for x in range(0, sticks):
sys.stdout.write('|')
print('')
# Remove sticks on request
def remove_sticks(lines, line, amount):
# Set line to the correct pointer
line -= 1
if lines[line] < amount:
lines[line] = 0
else:
lines[line] = lines[line] - amount
return lines
# Check if an input is an integer and in the correct range
def check_input(request_message, min_value, max_value, check_type, lines):
inputting = True
user_input = 0
while inputting:
user_input = input(request_message)
try:
# Check if the input is an integer
user_input = int(user_input)
# Make sure the input fits in our defined range
if max_value >= user_input > min_value:
inputting = False
# Check if the line has any sticks left
if check_type == 'line' and lines[user_input - 1] <= 0:
print('Error: Line is already empty')
inputting = True
else:
print('Error: Invalid range value entered')
except ValueError:
print('Error: String input entered')
# Return the input after checks
return user_input
def nim_sum(lines):
# First we need to calculate the multiples
nim_sum_total = 0
for (pointer, sticks) in enumerate(lines):
# Calculate multiples of 4
nim_sum_total += sticks // 4
sticks %= 4
# Calculate multiples of 2
nim_sum_total += sticks // 2
sticks %= 2
# Calculate multiples of 1
nim_sum_total += sticks // 1
return nim_sum_total % 2
# Check how many sticks are left
def lines_checksum(lines):
checksum = 0
# Calculate remaining sticks
for sticks in lines:
checksum += sticks
return checksum
# Check if a winner has been found
def winner_check(lines, player):
checksum = lines_checksum(lines)
# Return if we have a winner
if checksum == 1:
return player
else:
return 0

Everything in Python is passed by reference, so the lines variable in game_ai refers to the same list as the lines variable in your main program. Thus when you remove sticks from it, you end up clearing the shared lines variable.
To resolve this, you can make a copy of the lines first in game_ai, as lines = lines.copy().

Related

Restricting the domain of integer values accepted as input in python

I'm building a command line game using python.A main feature of this game is to get the user's input of either 1 or 2 as integer values.Any other character must be rejected.I used try-except & if-else condition to do this like shown below.I want to know whether there is any better method to get this done in one line or some other way without having to indent a whole bunch of code.
if __name__ == '__main__':
# INITIALIZE THE TOTAL STICKS , DEPTH OF THE TREE AND THE STARTINGG PLAYER
i_stickTotal = 11 # TOTAL NO OF STICKS IN THIS GAME
i_depth = 5 # THE DEPTH OF THE GOAL TREEE THE COMPUTER WILL BUILD
i_curPlayer = 1 # THIS WILL BE +1 FOR THE HUMAN AND -1 FOR THE COMPUTER
print("""There are 11 sticks in total.\nYou can choose 1 or 2 sticks in each turn.\n\tGood Luck!!""")
# GAME LOOP
while i_stickTotal > 0:
print("\n{} sticks remain. How many would you pick?".format(i_stickTotal))
try:
i_choice = int(input("\n1 or 2: "))
if i_choice - 1 == 0 or i_choice - 2 == 0:
i_stickTotal -= int(i_choice)
if WinCheck(i_stickTotal, i_curPlayer):
i_curPlayer *= -1
node = Node(i_depth, i_curPlayer, i_stickTotal)
bestChoice = -100
i_bestValue = -i_curPlayer * maxsize
# Determine No of Sticks to Remove
for i in range(len(node.children)):
n_child = node.children[i]
#print("heres what it look like ", n_child.i_depth, "and",i_depth)
i_val = MinMax(n_child, i_depth-1, i_curPlayer)
if abs(i_curPlayer * maxsize - i_val) <= abs(i_curPlayer*maxsize-i_bestValue):
i_bestValue = i_val
bestChoice = i
#print("Best value was changed # ", i_depth, " by " , -i_curPlayer, " branch ", i, " to ", i_bestValue)
bestChoice += 1
print("Computer chooses: " + str(bestChoice) + "\tbased on value: " + str(i_bestValue))
i_stickTotal -= bestChoice
WinCheck(i_stickTotal, i_curPlayer)
i_curPlayer *= -1
else:
print("You can take only a maximum of two sticks.")
except:
print("Invalid input.Only Numeric Values are accepted")
You can create a function to check user input and use below code.
while True:
var = int(input('Enter value (1 or 2) - '))
if var not in range(1, 3):
print('Invalid entry, please try again...')
continue
else:
break
Write a function that loops, calling input, until the value satisfies your constraint. Perhaps call it get_user_input. Then call that in your main function instead of input. For added value, pass a lambda into that function as a predicate to test the user input value - that'll make get_user_input more general.

Python printing before/after different lines

I have created some code long ago which helps to create a table in BBcode used in forums.
counter = 0
counter2 = 0
while True:
UserInput = input("")
if counter2 == 0:
print ("[tr]")
print ("[td][center]Label\n" + "[img]" + str(UserInput) + "[/img][/center][/td]")
counter += 1
counter2 += 1
if counter % 5 == 0:
print ("[/tr]")
So if i input Image1.jpg ~ Image7.jpg on seperate lines, the output is as shown below
> [tr]
> [td][center]Label[img]Image1.jpg[/img][/center][/td]
> [td][center]Label[img]Image2.jpg[/img][/center][/td]
> [td][center]Label[img]Image3.jpg[/img][/center][/td]
> [td][center]Label[img]Image4.jpg[/img][/center][/td]
> [td][center]Label[img]Image5.jpg[/img][/center][/td]
> [/tr]
> [td][center]Label[img]Image6.jpg[/img][/center][/td]
> [td][center]Label[img]Image7.jpg[/img][/center][/td]
Currently, the code only inserts [/tr] at the end of ever 5 images.How does one make it so that [/tr] is also printed at the end of output no matter how many jpgs are entered?
How can I print [tr] at the start and join it with the line below, and then not print again until a [/tr] has been printed?
Apologies for my crap English & explanation skills.
(Current progress)
counter = 0
while True:
UserInput = input("")
if counter == 0 or counter % 5 == 0:
print("[tr]", end = "")
print ("[td][center]Label\n" + "[img]" + str(UserInput) + "[/img][/center][/td]")
counter += 1
if counter % 5 == 0:
print("[/tr]")
After reading what you wrote 5 times I believe what you want is:
print("[tr]")
while True:
counter = 0
UserInput = input("")
if UserInput == "exit":
exit(0)
print("[tr]", end = "")
while (counter !=5):
print ("[td][center]Label\n" + "[img]" + str(UserInput) + "[/img][/center][/td]")
counter += 1
print ("[/tr]")
print("[/tr]")
So what happens here is you print [tr] in the same line as the first print from the inside while as you wanted. the [/tr] is in a new line but you can put it in the same by adding end = "" to the second print as well.
Separate the functions. Get the list of images, then process it:
def bbcode(images):
for i in range(0,len(images),5):
print('[tr]')
for image in images[i:i+5]:
print(f'[td][center]Label[img]{image}[/img][/center][/td]')
print('[/tr]')
def get_images():
images = []
while True:
image = input('Image? ')
if not image: break
images.append(image)
return images
images = get_images()
bbcode(images)
You can do it as one long script, but it isn't as clear:
count = 0
while True:
image = input('Image? ')
if not image:
break
count = (count + 1) % 5
if count == 1:
print('[tr]')
print(f'[td][center]Label[img]{image}[/img][/center][/td]')
if count == 0:
print('[/tr]')
if count != 0:
print('[/tr]')
Below is the result with some commentary. To update for your specifications, just set the max_item_blocks variable to whatever you want.
### your main body element with {} to pass a number
element = '[td][center]Label[img]Image{}.jpg[/img][/center][/td]'
### The number of "blocks" you want to print.
max_item_blocks = 3
### Define a start value of 1
start = 1
### Our simple loop with join() function
while max_item_blocks > 0:
### End value is start + 5
end = start + 5
print('[tr]\n' + '\n'.join([element.format(i) for i in range(start, end)]) + '\n[\\tr]')
### Start takes ending value
start = end
### Ending value is now start + 5
end = start + 5
### Reduce our block counts by 1
max_item_blocks -= 1
Output for 3 blocks:
[tr]
[td][center]Label[img]Image1.jpg[/img][/center][/td]
[td][center]Label[img]Image2.jpg[/img][/center][/td]
[td][center]Label[img]Image3.jpg[/img][/center][/td]
[td][center]Label[img]Image4.jpg[/img][/center][/td]
[td][center]Label[img]Image5.jpg[/img][/center][/td]
[\tr]
[tr]
[td][center]Label[img]Image6.jpg[/img][/center][/td]
[td][center]Label[img]Image7.jpg[/img][/center][/td]
[td][center]Label[img]Image8.jpg[/img][/center][/td]
[td][center]Label[img]Image9.jpg[/img][/center][/td]
[td][center]Label[img]Image10.jpg[/img][/center][/td]
[\tr]
[tr]
[td][center]Label[img]Image11.jpg[/img][/center][/td]
[td][center]Label[img]Image12.jpg[/img][/center][/td]
[td][center]Label[img]Image13.jpg[/img][/center][/td]
[td][center]Label[img]Image14.jpg[/img][/center][/td]
[td][center]Label[img]Image15.jpg[/img][/center][/td]
[\tr]

Why am I getting the variable not defined error?

The following is my code
n = int(input("please enter a value: "))
board = []
def make_board(n):
global board
max = n * n #the number of tiles in the board
count = 1 #a counter to change the value assigned to each tile
for i in range(n):
board.append([]) #appends a list inside the list of board. Essentially creates a row which is of type list.
for j in range(n):
num = max - count
if num == 0: #the 0 tile will display like a blank space
tile = ' '
elif num < 10: #adds a space to tile values less than 10 for formatting.
tile = ' ' + str(num)
else:
tile = str(num)
board[i].append(tile) #appends a tile value to each row, n number of times.
count += 1
if n%2 == 0:
tempvara = board[n-1][n-2]
tempvarb = board[n-1][n-3]
board[n-1][n-2]=tempvarb
board[n-1][n-3]=tempvara
#TODO
for row in board:
print(' '.join(row))
def find_blank(board):
global counterUNO
global counterDOS
global counterTRES
counterTRES = 0
#TODO
for i in range(n):
tempvari = board[i]
if ' ' in tempvari:
counterUNO = i
for z in board[counterUNO]:
counterTRES = counterTRES + 1
if ' ' in z:
counterDOS = counterTRES-1
break
tupleone = (counterUNO,counterDOS)
return(tupleone)
def find_tile(f):
counterfour = 0
tiles = str(input("tile BUBBER"))
if int(tiles)<10:
tiles = " "+tiles
counterfive = 0
countersixe = 0
countersixe = 0
for i in range(n):
chopstick = board[i]
if tiles in chopstick:
counterfour = i
for z in board[counterfour]:
countersixe = countersixe + 1
if tiles in z:
counterfive = countersixe-1
break
tupleDOS = (counterfour,counterfive)
return(tupleDOS)
def find_next_to_blank(board):
#print("here is the shit")
#print(find_tile(board))
vara = find_tile(board) #sets tile numb tuple to vara
varb = find_blank(board) #yeah
varc = int(tiles)
varaa = int(tiles[0])
varab = int(tiles[1])
varba = board[varaa+1][varab]
varbb = board[varaa][varab+1]
varbc = board[varaa-1][varab]
varbd = board[varaa][varab-1]
varbe = board[varaa+1][varab+1]
varbf = board[varaa-1][varab-1]
make_board(n)
#find_blank(board)
#find_tile(board)
find_next_to_blank(board)
Problem:
Right now I am trying to make a python Tile game where I can shift the numbers. the make board function obviously creates a board, i did it so that there are three lists in a big list and in the three list there are elements
and the find blank function identifies the coordinate of the non existing section of the board
and the find tile function is the function that the user inputs a value and the code identifies what is the coordinate of the tile that we want
So currently I am getting an error because when i am running the find next to blank function (the function is supposed to identify whether or not there is a blank spot next to the value which the user wants to input) i get the following error
Traceback (most recent call last):
File "python", line 149, in <module>
File "python", line 122, in find_next_to_blank
NameError: name 'tiles' is not defined
and i tried making "tiles" variable into a global one but it didn't work at all
The variable tiles is not defined in find_next_to_blank(board). I'd be remiss if I don't say this: consider restructuring your program to avoid using global variables.
Now that's out of the way, if you make tiles global, it ought to work.

I'm stuck in the creating of a Board game in python

I have an excercise to do and I'm stuck. It's the board game Alak, not much known, that I have to code in python. I can link the execrcise with the rules so you can help me better. The code has the main part and the library with all the procedures and function.
from Library_alak import *
n = 0
while n < 1:
n = int(input('Saisir nombre de case strictement positif : '))
loop = True
player = 1
player2 = 2
removed = [-1]
board = newboard(n)
display(board, n)
while loop:
i = select(board, n, player, removed)
print(i)
board = put(board, player, i)
display(board, n)
capture(board, n, player, player2)
loop = True if again(board, n, player, removed) is True else False
if player == 1 and loop:
player, player2 = 2, 1
elif player == 2 and loop:
player, player2 = 1, 2
win(board, n)
print(win(board, n))
And here is the library:
def newboard(n):
board = ([0] * n)
return board
def display(board, n):
for i in range(n):
if board[i] == 1:
print('X', end=' ')
elif board[i] == 2:
print('O', end=' ')
else:
print(' . ', end=' ')
def capture(board, n, player, player2):
for place in range(n):
if place == player:
place_beginning = place
while board[place] != player:
place_end = place
if board[place + x] == player:
return board
else:
return board
def again(board, n, player, removed):
for p in board(0):
if p == 0:
if p not in removed:
return True
else:
return False
def possible(n, removed, player, i, board):
for p in range(n + 1):
if p == 1:
if board[p-1] == 0:
if p not in removed:
return True
else:
return False
def win(board, n):
piecesp1 = 0
piecesp2 = 0
for i in board(0):
if i == 1:
piecesp1 += 1
else:
piecesp2 += 1
if piecesp1 > piecesp2:
print('Victory : Player 1')
elif piecesp2 > piecesp1:
print('Victory : Player 2')
else:
return 'Equality'
def select(board, n, player, removed):
loop = True
while loop:
print('player', player)
i = int(input('Enter number of boxes : '))
loop = False if possible(n, removed, player, i, board)is True else True
return i
def put(board, player, i):
i -= 1
if board[i] == 0:
if player == 1:
board[i] = 1
return board
else:
board[i] = 2
return board
else:
put(board, player, i)
So my problems here are that I have few errors, the first one is that when I enter the number '1' when asked to enter a number of boxes ( which is the place to play on ) nothing happens. Then when entering any other number, either the error is : if board[place + x] == player:
NameError: name 'x' is not defined
or there seems to be a problem with the : if board[place + x] == player:
NameError: name 'x' is not defined
I would appreciate a lot if anyone could help me. I'm conscious that it might not be as detailed as it should be and that you maybe don't get it all but you can contact me for more.
Rules of the Alak game:
Black and white take turns placing stones on the line. Unlike Go, this placement is compulsory if a move is available; if no move is possible, the game is over.
No stone may be placed in a location occupied by another stone, or in a location where a stone of your own colour has just been removed. The latter condition keeps the game from entering a neverending loop of stone placement and capture, known in Go as ko.
If placing a stone causes one or two groups of enemy stones to no longer have any adjacent empty spaces--liberties, as in Go--then those stones are removed. As the above rule states, the opponent may not play in those locations on their following turn.
If placing a stone causes one or two groups of your own colour to no longer have any liberties, the stones are not suicided, but instead are safe and not removed from play.
You shouldn't use "player2" as a variable, there's an easier way, just use "player" which take the value 1 or 2 according to the player. You know, something like that : player = 1 if x%2==0 else 2
and x is just a increasing int from 0 until the end of the game.

Monty Hall simulation not working as intended

I've been trying out to solve the monty hall problem in Python in order to advance in coding, which is why I tried to randomize everything. The thing is: I've been running into some trouble. As most of you probably know the monty problem is supposed to show that changing the door has a higher winrate (66%) than staying on the chosen door (33%). For some odd reason though my simulation shows a 33% winrate for both cases and I am not really sure why.
Here's the code:
from random import *
def doorPriceRandomizer():
door1 = randint(0,2) #If a door is defined 0, it has a price in it
door2 = randint(0,2) #If a door is defined either 1 or 2, it has a goat in it.
door3 = randint(0,2)
while door2 == door1:
door2 = randint(0,2)
while door3 == door2 or door3 == door1:
door3 = randint(0,2)
return door1,door2,door3 #This random placement generator seems to be working fine.
while True:
loopStart = 0
amountWin = 0
amountLose = 0
try:
loopEnd = int(input("How often would you like to run this simulation: "))
if loopEnd < 0:
raise ValueError
doorChangeUser = int(input("[0] = Do not change door; [1] = Change door: "))
if doorChangeUser not in range(0,2):
raise ValueError
except ValueError:
print("Invalid input. Try again.\n")
else:
while loopStart != loopEnd:
gameDoors = doorPriceRandomizer()
inputUser = randint(0,2)
if doorChangeUser == 0:
if gameDoors[inputUser] == 0:
amountWin += 1
loopStart += 1
else:
amountLose += 1
loopStart += 1
elif doorChangeUser == 1:
ChangeRandom = 0
while gameDoors[ChangeRandom] == gameDoors[inputUser]:
ChangeRandom = randint(0,2)
if gameDoors[ChangeRandom] == 0:
amountWin += 1
loopStart += 1
else:
amountLose += 1
loopStart += 1
print("Win amount: ",amountWin,"\tLose amount: ",amountLose)
What am I doing wrong? I really appreciate all help! Thanks in advance!
ChangeRandom = 0
while gameDoors[ChangeRandom] == gameDoors[inputUser]:
ChangeRandom = randint(0,2)
This doesn't do what you think it does. Instead of checking if the ChangeRandom door is the same as the inputUser door, this checks if the ChangeRandom door and the inputUser door have the same value -- that is to say they're either both winners or both losers.
That said, that's not even what you want to do. What you want to do is to find a door that's not the user's input that IS a loser door, then switch to the OTHER one that isn't the user's input. This could be implemented with minimal change to your code as:
other_wrong_door = next(c for c, v in enumerate(gameDoors) if v != 0 and c != inputUser)
new_door = next(c for c, _ in enumerate(gameDoors) if c != inputUser and c != other_wrong_door)
But honestly this merits a re-examining of your code's structure. Give me a few minutes to work something up, and I'll edit this answer to give you an idea of how I'd implement this.
import random
DOORS = [1, 0, 0]
def runonce(switch=False):
user_choice = random.choice(DOORS)
if user_choice == 1:
# immediate winner
if switch:
# if you won before and switch doors, you must lose now
return False
else:
new_doors = [0, 0] # remove the user-selected winner
new_doors = [0] # remove another loser
return bool(random.choice(new_doors))
# of course, this is always `0`, but
# sometimes it helps to show it. In production you
# wouldn't bother writing the extra lines and just return False
else:
if switch:
new_doors = [1, 0] # remove the user-selected loser
new_doors = [1] # remove another loser
return bool(random.choice(new_doors))
# as above: this is always True, but....
else:
return False # if you lost before and don't switch, well, you lost.
num_trials = int(input("How many trials?"))
no_switch_raw = [run_once(switch=False) for _ in range(num_trials)]
switch_raw = [run_once(switch=True) for _ in range(num_trials)]
no_switch_wins = sum(1 for r in no_switch_raw if r)
switch_wins = sum(1 for r in switch_raw if r)
no_switch_prob = no_switch_wins / num_trials * 100.0
switch_prob = switch_wins / num_trials * 100.0
print( " WINS LOSSES %\n"
f"SWITCH: {switch_wins:>4} {num_trials-switch_wins:>6} {switch_prob:.02f}\n"
f"NOSWITCH:{no_switch_wins:>4} {num_trials-no_switch_wins:>6} {no_switch_prob:.02f}")
You have gotten the mechanics of the problem wrong so you are getting the wrong result. I have rewritten the choice mechanics, but I am leaving the user input stuff to you so that you can continue to learn python. This is one of many ways to solve the problem, but hopefully it demonstrates some things to you.
def get_choices():
valid_choices = [0, 1, 2] # these are the values for a valid sample
shuffle(valid_choices) # now randomly shuffle that list
return valid_choices # return the shuffled list
def get_door(user_choice):
return user_choice.index(0)
def monty_sim(n, kind):
"""
:param n: number of runs in this simulation
:param kind: whether to change the door or not, 0 - don't change, 1 = change door
:return: (win_rate, 1 - win_rate)
"""
wins = 0
for i in range(0, n):
game_doors = get_choices()
user_choice = get_door(get_choices()) # use the same method and find user door choice
# so there are two branches.
# In both, a door with a goat (game_door = 1) is chosen, which reduce the result to
# a choice between two doors, rather than 3.
if kind == 0:
if user_choice == game_doors.index(0):
wins += 1
elif kind == 1:
# so now, the user chooses to change the door
if user_choice != game_doors.index(0):
wins += 1
# Because the original choice wasn't the right one, then the new
# must be correct because the host already chose the other wrong one.
win_rate = (wins / n) * 100
return win_rate, 100 - win_rate
if __name__ == '__main__':
n = 1000
kind = 1
wins, loses = monty_sim(n, kind)
print(f'In a simulation of {n} experiments, of type {kind} user won {wins:02f} of the time, lost {loses:02f} of the time')

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