Develop Reference

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.

How to move my character on my generated board?

A few days ago a started making my simple board game. First of all, I generate a board for the game. It looks like this:
the gameboard generated for 13x13
Secondly, I place my character on the board, which is 'A':
The player placed
I made a dice for it which generates numbers from 1 to 6.
My goal right now is to get the 'A' character moving around by the dice on the '*' symbols, until it gets at the top left corner:
I need to get here by the dice
So here is my code that I tried:
import math
import random
import os
board= []
def generator(boardsize):
for row in range(boardsize+1):
brow = []
for column in range(boardsize+1):
if row == column == 0:
brow.append(' ')
elif row==0:
brow.append(str(column-1)[-1])
elif column==0:
brow.append(str(row-1)[-1])
elif ((math.ceil(boardsize/2)-1 )<= column) and(column <= (math.ceil(boardsize/2)+1)) or ((math.ceil(boardsize/2)-1 )<= row) and(row <= (math.ceil(boardsize/2)+1)):
if row == 1 or column == 1 or row == boardsize or column == boardsize:
brow.append('*')
else:
if row == (math.ceil(boardsize/2)) and column == (math.ceil(boardsize/2)):
brow.append('X')
elif row == (math.ceil(boardsize/2)) or column == (math.ceil(boardsize/2)):
brow.append('D')
else:
brow.append('*')
else:
brow.append(' ')
board.append(brow)
return board
def print_table(x):
os.system('cls')
for x in board:
print(' '.join(x))
number_from_dice= []
def dice():
min = 1
max = 6
x = random.randint(min, max)
number_from_dice[:]= [x]
return number_from_dice
def player1(x):
generator(x)
prev_char_y = 1
prev_char_x = math.ceil(x/2)+1
char_y= 1
char_x= math.ceil(x/2)+1
board[char_y][char_x] = "A"
print_table(x)
dice()
f = number_from_dice[0]
for i in range(f):
if(char_y<x):
if (board[char_y+1][char_x]) == '*':
char_y= char_y +1
board[char_y][char_x] = "A"
board[prev_char_y][prev_char_x] = '*'
prev_char_x = char_x
prev_char_y = char_y
print_table(x)
else:
if(char_x!=x):
char_x2 = char_x
if (board[char_y][char_x+1]=='*'):
char_x = char_x +1
board[char_y][char_x] = "A"
board[prev_char_y][prev_char_x] = '*'
prev_char_x = char_x
prev_char_y = char_y
print_table(x)
else:
if (board[char_y+1][char_x]) == '*':
char_y= char_y +1
board[char_y][char_x] = "A"
board[prev_char_y][prev_char_x] = '*'
prev_char_x = char_x
prev_char_y = char_y
print_table(x)
else:
if (board[char_y][char_x2-1]) == '*':
char_x2 = char_x2 -1
board[char_y][char_x2] = "A"
board[prev_char_y][prev_char_x] = '*'
prev_char_x = char_x2
prev_char_y = char_y
print_table(x)
else:
if (board[char_y+1][char_x2]) == '*':
char_y = char_y +1
board[char_y][char_x2] = "A"
board[prev_char_y][prev_char_x] = '*'
prev_char_x = char_x2
prev_char_y = char_y
print_table(x)
print('Number from dice: ', end='')
print(f)
player1(13)
Does the technic I used have potential? Or is it too complicated? How would you do it?

Just in a generic sense you've made it overly complicated.
Consider this - the board, as far as movement is concerned, is just a set of ordered spaces.
But right now you have information about how the board is created as part of the player code.
Best to separate this, and you will find that things get simpler.
Instead, have the player simply track it's progress, in other words, what numbered space is it on.
Then you can generate the board and, knowing the space numbers, you can see if it matches the player location.
And then take it one step further (and simpler still) and just draw the board on a 2D array, and then output that, instead of trying to figure out the board as you go line-by-line.

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')

Conway's Game of Life using Sparse Matrix (Python)

I am writing the game of life in python using a Sparse Matrix. My program takes coordinates from user input and sets the cells at the chosen coordinates to be alive. I have it to where it will print the first generation, but I can't seem to figure out why it wont print any subsequent generations. Any help would be appreciated.
class SparseLifeGrid:
generations = list()
def __init__(self):
"""
"pass" just allows this to run w/o crashing.
Replace it with your own code in each method.
"""
self._mat = list()
self.col = []
self.row = []
def minRange(self):
"""
Return the minimum row & column as a tuple.
"""
for i in range(len(self.row)):
if self.row[i] < self.minRow:
self.minRow = self.row[i]
if self.col[i] < self.minCol:
self.minCol = self.col[i]
min_Range = [self.minRow,self.minCol]
return min_Range
def maxRange(self):
"""
Returns the maximum row & column as a tuple.
"""
for i in range(len(self.row)):
if self.row[i] > self.maxRow:
self.maxRow = self.row[i]
if self.col[i] > self.maxCol:
self.maxCol = self.col[i]
max_Range = [self.maxRow,self.maxCol]
return max_Range
def configure(self,coordList):
"""
Set up the initial board position.
"coordlist" is a list of coordinates to make alive.
"""
# for i in coordList:
# self.setCell(i[0],i[1])
self._mat = list()
self.coordList = coordList
for i in range(len(self.coordList)):
spot = self.coordList[i]
self.row += [spot[0]]
self.col += [spot[1]]
self._mat += [[self.row[i],self.col[i]]]
self.maxRow = self.minRow = self.row[0]
self.maxCol = self.minCol = self.col[0]
def clearCell(self,row, col):
"""
Set the cell to "dead" (False)
"""
self[row,col] = 0
def setCell(self,row, col):
"""
Set the cell to "live" (True") and if necessary, expand the
minimum or maximum range.
"""
self[row,col] = 1
def isLiveCell(self,row,col):
n = len(self.coordList)
for i in range(n):
if (self._mat[i] == [row,col]):
return True
return False
def numLiveNeighbors(self, row,col):
"""
Returns the number of live neighbors a cell has.
"""
neighbors = 0
if self.isLiveCell(row+1,col): #checks below the current cell
neighbors += 1
if self.isLiveCell(row-1,col): #checks above the current cell
neighbors += 1
if self.isLiveCell(row,col+1): #checks to the right of the current cell
neighbors += 1
if self.isLiveCell(row,col-1): #checks to the left of the current cell
neighbors += 1
if self.isLiveCell(row+1,col+1): #checks downwards diagonally to the right of the current cell
neighbors += 1
if self.isLiveCell(row+1,col-1): #checks downwards diagonally to the left of the current cell
neighbors += 1
if self.isLiveCell(row-1,col+1): #checks upwards diagonally to the right of the current cell
neighbors += 1
if self.isLiveCell(row-1,col-1): #checks upawards diagonally to the left of the current cell
neighbors += 1
return neighbors
def __getitem__(self,ndxTuple):
row = ndxTuple[0]
col = ndxTuple[1]
if(self.isLiveCell(row,col)==1):
return 1
else:
return 0
def __setitem__(self,ndxTuple, life):
"""
The possible values are only true or false:
True says alive, False for dead.
Also, check to see if this cell is outside of the maximum row and/or
column. If it is, modify the maximum row and/or maximum column.
"""
ndx = self._findPosition(ndxTuple[0],ndxTuple[1])
if ndx != None:
if life != True:
self._mat[ndx].value = life
else:
self._mat.pop[ndx]
else:
if life != True:
element = _GoLMatrixElement(ndxTuple[0],ndxTuple[1],life)
self._mat.append(element)
def _findPosition(self,row,col):
''' Does a search through the matrix when given the row&col and
returns the index of the element if found
'''
n = len(self._mat)
for i in range(n):
if (row == self._mat[i]) and (col == self._mat[i]):
return i
return None
def __str__(self):
"""
Print a column before and after the live cells
"""
s=""
maxRange=self.maxRange()
minRange=self.minRange()
for i in range(minRange[0]-1,maxRange[0]+2):
for j in range(minRange[1]-1,maxRange[1]+2):
s+=" "+str(self[i,j])
s+="\n"
return s
def getCopy(self):
"""
Return a copy of the current board object, including the max and min
values, etc.
"""
return SparseLifeGrid()
def evolve(self):
"""
Save the current state to the "generations" list.
Based on the current generation, return the next generation state.
"""
self.generations.append(self._mat)
for row in range(len(self.row)):
for col in range(len(self.col)):
if ((self[row,col] == True) and (self.numLiveNeighbors(row,col) == 2)):
self.setCell(row,col)
if ((self[row,col] == True) and (self.numLiveNeighbors(row,col) == 3)):
self.setCell(row,col)
if ((self[row,col] == True) and (self.numLiveNeighbors(row,col) < 2)):
self.clearCell(row,col)
if ((self[row,col] == True) and (self.numLiveNeighbors(row,col) > 3)):
self.clearCell(row,col)
if ((self[row,col] == False) and (self.numLiveNeighbors(row,col) == 3)):
self.setCell(row,col)
self.generations.append(self._mat)
return self._mat
def hasOccurred(self):
"""
Check whether this current state has already occured.
If not, return False. If true, return which generation number (1-10).
"""
for i in range(len(self.generations)):
if len(self.generations) > 0:
print("This is generation",len(self.generations))
return self.generations[i]
else:
print("No Generations")
return False
def __eq__(self,other):
"""
This is good method if we want to compare two sparse matrices.
You can just use "sparseMatrixA == sparseMatrixB" once this method
is working.
"""
pass
class _GoLMatrixElement:
"""
Storage class for one cell
"""
def __init__(self,row,col):
self.row = row
self.col = col
self.next = None #
# Since this node exists, this cell is now alive!
# To kill it, we just delete this node from the lists.
from SparseLifeGrid import SparseLifeGrid
import sys
def readPoints(lifeGrid):
"""
Reads the locations of life and set to the SparseMatrix
"""
print("1. Enter positions of life with row,col format (e.g., 2,3).")
print("2. Enter empty line to stop.")
life=input()
coordList=[]
while life:
points=life.split(",")
try:
coord=[int(points[0]),int(points[1])]
coordList.append(coord)
except ValueError:
print("Ignored input:" + life+ ", row, col not valid numbers")
except:
print("Unexpected error:", sys.exc_info()[0])
print("added, keep entering or enter empty line to stop.")
life=input()
print("Thanks, finished entering live cells")
lifeGrid.configure(coordList)
def main():
"""
Runs for ten generations if a stable (repeating) state is not found.
"""
lifeGrid= SparseLifeGrid()
readPoints(lifeGrid)
patterns=0
i=0
while i <10 :
"""
Evolve to the next generation
"""
lifeGrid.evolve()
print(lifeGrid)
"""
Check whether this generation is a repetition of any of the
previous states.
If yes return the previous matching generation (1-10).
"""
patterns=lifeGrid.hasOccurred()
if patterns != -1:
break
i+=1
if i==10:
print("No pattern found")
else:
print("Pattern found at: " + str(i)+ " of type: " + str(patterns))
main()

The loop only executes once because of this:
patterns=lifeGrid.hasOccurred()
if patterns != -1:
break
patterns will never equal -1 under any circumstance, since hasOccurred can only return False or a member of self.generations or None. As a result, the loop will always break in the first iteration, and no subsequent generations will be printed.
Incidentally, your hasOccurred logic is strange. if len(self.generations) equals zero, then the loop will not get executed at all, and none of your return statements will be evaluated, so the result will be None. If the length is greater than zero, then the condition within the loop is always True, so self.generations[i] is always returned in the first iteration. Perhaps you meant to do:
#changed the name from `hasOcurrence`, since that implies the method can only return True or False.
def get_last_occurrence(self):
for i in range(len(self.generations)):
#todo: somehow compare self.generations[i] to the current generation
if the generations match:
return i
#the loop ended without finding a match!
return False
Then, within main:
patterns=lifeGrid.hasOccurred()
if patterns != False:
break

Invalid syntax with spacing my list

I'm getting a invalid syntax with def spread_row()
I have a text file and it works fine in that but when i copy it into the final coding, it won't work. Help?
What I'm trying to do is make a 3x3 grid of random 1's and 0's. The code is incomplete so some of the coding doesn't so anything yet.
##variables to control all the games
##number of games played and points collected in total
games_so_far = 0
total_points = 0
## FOR ONE GAME
## variables that will be used for one single game
max_change = 0
## SUBROUTINES AND FUNCTIONS
import random
def invite_to_play():
play = raw_input("Would you like to play " + ask_again + "? (y/n): ")
if play == "y" or play == "Y":
play_response = True
else:
play_response = False
return play_response
def computer_play():
computer = raw_input("Would you like that the computer also plays? (y/n): ")
if computer =="y" or computer =="Y":
computer_response = True
else:
computer_response = False
return computer_response
def ask_user_int(question):
response = raw_input(question)
while not (response.isdigit()):
print "Your input must be an integer number"
response = raw_input(question)
return int(response)
def generate_random_number(dim):
## Generate a board of 0's and 1's, up to the size set in "dim"
return [random.randint(0,1) for i in range(dim)
def spread_row():
## Spaces the numbers evenly
for dat in data:
print " ".join(map(str, dat))
return data
def stop_max_changes()
print "No more changes, the game is over!"
return
def program_evaluates_board(numbers):
## Evaluates the rows and cols to see if they are even or odd
row1 = sum(data[0])
col1 = sum(row[0] for row in data)
row2 = sum(data[1])
col2 = sum(row[1] for row in data)
row3 = sum(data[2])
col3 = sum(row[2] for row in data)
if row1%2 == 0:
print "False"
else:
print "True"
return
## TOP LEVEL
print 'Welcome to the "An odd matrix" game' + \
"====================================="
games_so_far = 0
wants_to play = invite_to_play("")
computer = computer_play()
## LOOP TO PLAY MORE GAMES
while wants_to_play:
games_so_far = games_so_far + 1
num = ask_user_int("Size of board (between 3 and 6 inclusive): ")
dim = int(num)
data = [random_row(dim) for i in range(dim)]
spread_row()
print "The board is"
print "-------------"
print "\n(initial board)"
print "\n Col 0 Col 1 Col 2"
max_changes = ask_user_int("How many changes would you like to do?" + \
"\n > 0 and <= 2: ")
changes_so_far = 0

first of all , you missing a ":"
def stop_max_changes(): # missing : there
second, why there is a space in this return value ?:
wants_to play = invite_to_play("") # why space here ?
third, you are missing a right bracket
def generate_random_number(dim):
## Generate a board of 0's and 1's, up to the size set in "dim"
return [random.randint(0,1) for i in range(dim)
pls past full code , I can make full diagnose here ..