Question

我正在尝试创建一个Tile类，并在另一种方法中使用它。但是，当我运行下面的代码时，会引发错误：AttributeError: type object 'Tile' has no attribute 'row'。

当我从队列（Python列表）中弹出类并尝试打印时，它会打印该行的值（为0），但会给出AttributeError。

为什么说属性行不存在？

"""
Shortest distance between two cells in a matrix or grid

"""

class Tile:
  def __init__(self, row, col, dist):  
    self.row = row
    self.col = col
    self.dist = dist

def min_path(rows, cols, lot):
  start_node = Tile(0, 0, 0)
  q = []
  q.append(start_node)
  visited = [[False]*cols for i in range(rows)]

  for i in range(rows):
    for j in range(cols):
      if lot[i][j] == 0:
        visited[i][j] = True

  while q:
    new_tile = q.pop(0)

    print(new_tile.row)

    if lot[new_tile.row][new_tile.col] == 9:
      return new_tile.dist

    if new_tile.row - 1 >= 0 and visited[new_tile.row - 1][new_tile.col] == False:
      Tile(new_tile.row - 1, new_tile.col, new_tile.dist + 1)
      q.append(Tile)
      visited[new_tile.row - 1][new_tile.col] = True

    if new_tile.row + 1 < rows and visited[new_tile.row + 1][new_tile.col] == False:
      Tile(new_tile.row + 1, new_tile.col, new_tile.dist + 1)
      q.append(Tile)
      visited[new_tile.row + 1][new_tile.col] = True

    if new_tile.col - 1 >= 0 and visited[new_tile.row][new_tile.col - 1] == False:
      Tile(new_tile.row, new_tile.col - 1, new_tile.dist + 1)
      q.append(Tile)
      visited[new_tile.row][new_tile.col - 1] = True

    if new_tile.col + 1 < cols and visited[new_tile.row][new_tile.col + 1] == False:
      Tile(new_tile.row, new_tile.col + 1, new_tile.dist + 1)
      q.append(Tile)
      visited[new_tile.row][new_tile.col + 1] = True

  return -1


if __name__ == "__main__":
  lot = [
    [1, 0, 0, 0],
    [1, 0, 1, 0],
    [1, 1, 0, 0],
    [0, 1, 9, 0],
  ]
  result = min_path(4, 4, lot)
  print(result)

当我运行此文件时，这是输出：

0
Traceback (most recent call last):
  File "code.py", line 568, in <module>
    result = min_path(4, 4, lot)
  File "code.py", line 533, in min_path
    print(new_tile.row)
AttributeError: type object 'Tile' has no attribute 'row'

Answer 1

似乎是由于以下几行：q.append(Tile)。您将对类本身的引用而不是其实例附加。而是尝试类似

tile = Tile(new_tile.row - 1, new_tile.col, new_tile.dist + 1)
q.append(tile)

为什么即使属性确实存在，Python为何也会给出AttributeError

1 个答案: