如何在多维数组中找到特定值？

Question

我正在制作一个类似跳棋的游戏，以创建我使用多维数组的棋盘。我在每个空白处填充数组0，然后一组芯片由1表示，另一组由2表示。有没有什么方法可以获得每套芯片占用的空间列表？这是我的游戏键盘：

matrix = [[1,1,1,1,1,0,0,0,0,0], [1,1,1,1,0,0,0,0,0,0], 
      [1,1,1,0,0,0,0,0,0,0], [1,1,0,0,0,0,0,0,0,0], 
      [1,0,0,0,0,0,0,0,0,0], [0,0,0,0,0,0,0,0,0,2], 
      [0,0,0,0,0,0,0,0,2,2], [0,0,0,0,0,0,0,2,2,2], 
      [0,0,0,0,0,0,2,2,2,2], [0,0,0,0,0,2,2,2,2,2]] 

print "\n".join(" ".join(str(el) for el in row) for row in matrix) 

Answer 1

虽然列表内涵通常是构建单个列表的好方法，您必须多次遍历整个矩阵才能找到每个可能芯片值的位置。

matrix = [[1,1,1,1,1,0,0,0,0,0], [1,1,1,1,0,0,0,0,0,0], 
      [1,1,1,0,0,0,0,0,0,0], [1,1,0,0,0,0,0,0,0,0], 
      [1,0,0,0,0,0,0,0,0,0], [0,0,0,0,0,0,0,0,0,2], 
      [0,0,0,0,0,0,0,0,2,2], [0,0,0,0,0,0,0,2,2,2], 
      [0,0,0,0,0,0,2,2,2,2], [0,0,0,0,0,2,2,2,2,2]] 

positions = {} 
for y in xrange(len(matrix)): 
    for x in xrange(len(matrix)): 
     positions.setdefault(matrix[y][x], []).append((y, x)) 

# show the all positions of each chip value 
for chip in sorted(positions): 
    print('{}: {}'.format(chip, positions[chip])) 

输出：

0: [(0, 5), (0, 6), (0, 7), (0, 8), (0, 9), (1, 4), (1, 5), (1, 6), (1, 7), (1, 8), (1, 9), (2, 3), (2, 4), (2, 5), (2, 6), (2, 7), (2, 8), (2, 9), (3, 2), (3, 3), (3, 4), (3, 5), (3, 6), (3, 7), (3, 8), (3, 9), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (4, 6), (4, 7), (4, 8), (4, 9), (5, 0), (5, 1), (5, 2), (5, 3), (5, 4), (5, 5), (5, 6), (5, 7), (5, 8), (6, 0), (6, 1), (6, 2), (6, 3), (6, 4), (6, 5), (6, 6), (6, 7), (7, 0), (7, 1), (7, 2), (7, 3), (7, 4), (7, 5), (7, 6), (8, 0), (8, 1), (8, 2), (8, 3), (8, 4), (8, 5), (9, 0), (9, 1), (9, 2), (9, 3), (9, 4)] 
1: [(0, 0), (0, 1), (0, 2), (0, 3), (0, 4), (1, 0), (1, 1), (1, 2), (1, 3), (2, 0), (2, 1), (2, 2), (3, 0), (3, 1), (4, 0)]                                                                                                               
2: [(5, 9), (6, 8), (6, 9), (7, 7), (7, 8), (7, 9), (8, 6), (8, 7), (8, 8), (8, 9), (9, 5), (9, 6), (9, 7), (9, 8), (9, 9)]                                                                                                               

Answer 2

您可以使用列表理解与条件，下面的代码返回由2所占据的所有空间：

[(y, x) for y in xrange(len(matrix)) for x in xrange(len(matrix[y])) if matrix[y][x] == 2] 

输出：

[(5, 9), (6, 8), (6, 9), (7, 7), (7, 8), (7, 9), (8, 6), (8, 7), (8, 8), (8, 9), (9, 5), (9, 6), (9, 7), (9, 8), (9, 9)]