Python：將對象存儲在二維數組中並調用其方法

Question

我正在嘗試製作國際象棋應用程序。代碼如下：

#file containing pieces classes 
class Piece(object):` 

    name = "piece" 
    value = 0 
    grid_name = "____" 


class Pawn(Piece): 

# Rules for pawns. 
#If first move, then can move forward two spaces 

name = "Pawn" 
value = 1 
grid_name = "_PN_" 
first_move = True 


#Main file 
from Piece import * 



class GameBoard: 

    pieces = [] 
    grid = [][] 

    def __init__(self): 

     self.grid[1][0] = self.pieces.append(Pawn()) 



currentBoard = GameBoard() 

我想呼籲位於網格對象變量的值[1] [0]

它看起來是這樣的：

print currentBoard.grid[1][0].value 

此代碼沒有按」告訴我我錯過了一些關於對象和變量範圍的東西。這是Python中可能的東西嗎？

編輯 - 解決方案

我沒有找到一個解決方案，這在使用網格的列表來保存在片列表中的對象的索引的參考。下面的代碼：

class GameBoard: 

    # initialize empty board 
    grid = [["____" for i in range(8)] for j in range(8)] 
    pieces = [] 

    def __init__(self): 

     self.grid[0][0] = 0 
     self.grid[0][1] = 1 
     self.grid[0][2] = 2 
     self.grid[0][3] = 3 
     self.grid[0][4] = 4 
     self.grid[0][5] = 5 
     self.grid[0][6] = 6 
     self.grid[0][7] = 7 
     self.grid[1][0] = 8 
     self.grid[1][1] = 9 
     self.grid[1][2] = 10 
     self.grid[1][3] = 11 
     self.grid[1][4] = 12 
     self.grid[1][5] = 13 
     self.grid[1][6] = 14 
     self.grid[1][7] = 15 


pieces = [] 

pieces.append(Pawn()) 

#grid will return the integer which can be passed to the other list to pull an 
#object for using the .value attribute 

print pieces[currentBoard.grid[1][0]].value 

Answer 1

重寫你的代碼，以便它只是運行作爲一個單獨的文件：

#file containing pieces classes 
class Piece(object): 
    name = "piece" 
    value = 0 
    grid_name = "____" 


class Pawn(Piece): 
    # Rules for pawns. 
    #If first move, then can move forward two spaces 

    name = "Pawn" 
    value = 1 
    grid_name = "_PN_" 
    first_move = True 

class GameBoard: 

    pieces = [] 
    grid = [[],[]] 

    def __init__(self): 

     self.grid[0][1] = self.pieces.append(Pawn()) 



currentBoard = GameBoard() 

有一些需要加以糾正的幾件事情。首先，Piece,Pawn和GameBoard中定義的變量未在__init__()方法下定義。這意味着這些變量將被該類的所有實例共享。

例子：

>>> pawn1 = Pawn() # Make two Pawns 
>>> pawn2 = Pawn() 
>>> print pawn1.first_move, pawn2.first_move 
True, True 
>>> pawn1.first_move = False # Change the first pawns attribute 
>>> print pawn1.first_move, pawn2.first_move # But both change 
False, False 

爲了避免這種情況，定義方法__init__()下你的類屬性的所有三個你的類。

實施例：

class Pawn(Piece): 
    # Rules for pawns. 
    #If first move, then can move forward two spaces 
    def __init__(self): 
     self.name = "Pawn" 
     self.value = 1 
     self.grid_name = "_PN_" 
     self.first_move = True 

接着，您的可變grid未在python正確定義。如果你想用兩個空名單列表，你可以做以下

grid = [[], []] 

但是一個簡單的方法，使空列表的一個8x8結構將是做到以下幾點

grid = [[[] for i in xrange(8)] for j in xrange(8)]