Question

我正在通过OReilly Technical School上课，其任务是将2-d array class与列表implementation一起调整为3-d array class。

这是我的改编：


import array as sys_array

class array:

def __init__(self, M, N, O):
    "Create 3-D array of lists stuffed with zeroes"
    self._data = sys_array.array("i", [0] * M * N * O)
    self._rows = M
    self._cols = N
    self._depth = O

def __getitem__(self, key):
    "returns the appropriate element for a three-element tuple subscript tuple."
    row, col, depth = self._validate_key(key)
    return self._data[row*self._cols+col*self._depth+depth]

def __setitem__(self, key, value):
    "sets the appropriate element for a three-element subscript tuple."
    row, col, depth = self._validate_key(key)
    self._data[row*self._cols+col*self._depth+depth] = value

def _validate_key(self, key):
    """Validates a key against the array's shape, returning good tuples.
    Raises KeyError on problems."""
    row, col, depth = key
    if (0 <= row < self._rows and 0 <= col < self._cols and 0 <= depth < self._depth):
        return key
    raise KeyError("subscript out of range")

当我使用以下代码测试它时，我遇到了问题，我怀疑是def __init__(self, M, N, O): "Create 3-D array of lists stuffed with zeroes" self._data = sys_array.array("i", [0] * M * N * O) self._rows = M self._cols = N self._depth = O def __getitem__(self, key): "returns the appropriate element for a three-element tuple subscript tuple." row, col, depth = self._validate_key(key) return self._data[row*self._cols+col*self._depth+depth] def __setitem__(self, key, value): "sets the appropriate element for a three-element subscript tuple." row, col, depth = self._validate_key(key) self._data[row*self._cols+col*self._depth+depth] = value def _validate_key(self, key): """Validates a key against the array's shape, returning good tuples. Raises KeyError on problems.""" row, col, depth = key if (0 <= row < self._rows and 0 <= col < self._cols and 0 <= depth < self._depth): return key raise KeyError("subscript out of range")和getitem语句，特别是 setitem索引短语，但如果有的话我在这里没有看到问题。这是测试代码和问题：

self._data[row*self._cols+col*self._depth+depth]

我不应该得到任何＆＃34;掷骰子！＆＃34;但是我愿意。谁能帮我看看我错过了什么？

谢谢！戴夫

Answer 1

在计算数组索引时需要考虑_depth。

def __getitem__(self, key):
    "returns the appropriate element for a three-element tuple subscript tuple."
    row, col, depth = self._validate_key(key)
    return self._data[row*self._cols*self._depth + col*self._depth + depth]

def __setitem__(self, key, value):
    "sets the appropriate element for a three-element subscript tuple."
    print(key)
    row, col, depth = self._validate_key(key)
    self._data[row*self._cols*self._depth + col*self._depth + depth] = value

以防万一：用于调试的print语句：

def __str__(self):
    '''
    '''
    ret = ''
    for row in range(self._rows):
        for col in range(self._cols):
            for depth in range(self._depth):
                print(row, col, depth)
                ret += '{} '.format(self[row, col, depth])
            ret += '\n'
        ret += '\n'
    return  ret

python3 3d数组类作为列表

1 个答案: