Bishop Chess | Python Fiddle

import pprint

class Board:

def __init__(self):
		self.board = [["r", "b", "n", "q", "k", "n", "b", "r"],
        		["p", "p", "p", "p", "p", "p", "p", "p"],
        		["", "", "", "", "", "", "", ""],
        		["", "", "", "", "", "", "", ""],
        		["", "", "", "", "", "", "", ""],
        		["", "", "", "", "", "", "", ""],
        		["", "", "", "", "", "", "", ""],
        		["", "", "", "", "", "", "", ""],
        		["P", "P", "P", "P", "P", "P", "P", "P"],
        		["R", "Bb", "N", "Q", "K", "N", "B", "R"]]

@staticmethod
	def isInsideBoard(x,y):
        	if (x < 0) or (x > 8) or (y < 0) or (y > 8):
            		return False
        	else:
            		return True
                
 ####### end of Board class

class Bishop:

def __init__(self, x, y):
        self.x = x    # instance variable unique to each instance
        self.y = y
        
    def getDiagonalCoordinates(self): 
        directions = [[1,1],[-1,1],[-1,-1],[1,-1]]
        moves = []
        for direction in directions: #search for squares in every direction diagonally around the piece
            possible_x = self.x; #set the starting point back to the piece's actual location
            possible_y = self.y;
            for counter in range(0,8):
            possible_x = possible_x+direction[0];
            possible_y = possible_y+direction[1];
                if(Board.isInsideBoard(possible_x,possible_y)): #creates an instance, but it immediately dissapears. This IS NOT the main board used for the game, we're only using it for the helper method
                moves.append([possible_x,possible_y])
            else: #the move isn't on the board. Don't add it to the moves list, and quit this loop
                break
        return moves
        
    def getPossibleMoves(self):
        possibleMoves = self.getDiagonalCoordinates()
        #later on subtract impossible moves due to other pieces here
            return possibleMoves
    
        def setPosition(self,x,y):
        self.x = x
        self.y = y

##### End of Bishop Class

board = Board() #the copy of the board for the game. Not really used for anything right now
B1 = Bishop(4,6) #make one instance of the bishop class and initialize it at a position
B2 = Bishop(0,2) #make a different instance of the bishop class

print("Current location if B1 - X: {} Y: {}".format(B1.x, B1.y))
pprint.pprint(B1.getPossibleMoves())

print("Current location if B2 - X: {} Y: {}".format(B2.x, B2.y))
pprint.pprint(B2.getPossibleMoves())

print("moving B1")
B1.setPosition(1,3)
print("Current location - X: {} Y: {}".format(B1.x, B1.y))
pprint.pprint(B1.getPossibleMoves())

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