I'm writing a program that is supposed to simulate a game board made up of a row of squares. On each square, the player rolls a 3-sided die that can come up 1, 2, or 3. Based on the roll, the player moves ahead that many spaces. To simulate this, each square links to 3 other squares: the one in front of it, the next one over, and the one after that. So for example...
square 1:
roll 1 -> square 2 ...
roll 2 -> square 3 ...
roll 3 -> square 4
The problem is, whenever I set the links for one square, it also sets the links for all the squares. In other words, the program is acting as though the list of links is a global variable instead of a class variable. I am totally puzzled by this.
When I print out the results, this is what I expect:
Square 1: 1 -> 2 ... 2 -> 3 ... 3 -> 4
Square 2: 1 -> 3 ... 2 -> 4 ... 3 -> 5
Square 3: 1 -> 4 ... 2 -> 5 ... 3 -> 6
But instead, this is what I get:
Square 1: 1 -> 2 ... 2 -> 3 ... 3 -> 4
Square 2: 1 -> 2 ... 2 -> 3 ... 3 -> 4
Square 3: 1 -> 2 ... 2 -> 3 ... 3 -> 4
Here is the total code:
class Square:
links = {}
number = -1
def __init__(self, num):
self.number = num
def addLink(self, destination, distance):
if(distance < 0 or distance > 3):
print("ERROR: invalid distance " + str(distance) + " being linked from Square " + str(self.number) + " to " + str(destination.number))
return;
while(destination.hasJump()):
destination = destination.getJumpDest()
self.links[distance] = destination
def getLink(self, n):
return self.links[n]
def hasJump(self):
return 0 in self.links
def getJumpDest(self):
return self.links[0]
def printSummary(self):
if(self.hasJump()):
print("Square " + str(self.number) + ": 0 -> " + str(self.getJumpDest().number))
else:
print("Square " + str(self.number) + ":")
if(1 in self.links):
print("1 -> " + str(self.getLink(1).number))
if(2 in self.links):
print("2 -> " + str(self.getLink(2).number))
if(3 in self.links):
print("3 -> " + str(self.getLink(3).number))
class Board:
squares = {}
size = 0
def __init__(self, boardSize = 5):
self.size = boardSize
for n in range(boardSize, 0, -1):
thisSquare = Square(n);
if(n < boardSize-1):
thisSquare.addLink(self.squares[(n+1)], 1)
if(n < boardSize-2):
thisSquare.addLink(self.squares[(n+2)], 2)
if(n < boardSize-3):
thisSquare.addLink(self.squares[(n+3)], 3)
self.squares[n] = thisSquare
def createJump(start, finish):
self.squares[start].addLink(self.squares[finish],True)
game = Board()
for n in range(1,5):
game.squares[n].printSummary()
I've been working on this bug for about an hour and a half now and I've concluded that either I am missing something obvious, or there is something I don't understand about class variables in Python. I would very much appreciate any assistance.
Thank you so much!
