康威的生命游戏指数错误

Question

所以我必须用5条规则来做康威的生命游戏：

1. 活动邻居少于两个的单元格
2. 有超过3个活邻居的单元格
3. 一个已经死亡且正好有3个活着的邻居的牢房正在栩栩如生
4. 所有边缘单元格保持为0
5. 所有其他单元格保持其状态

示例：

>>> A = [ [0,0,0,0,0],
      [0,0,1,0,0],
      [0,0,1,0,0],
      [0,0,1,0,0],
      [0,0,0,0,0]]

>>> printBoard(A)
00000
00100
00100
00100
00000

>>> A2 = next_life_generation( A )
>>> printBoard(A2)
00000
00000
01110
00000
00000

>>> A3 = next_life_generation( A2 )
>>> printBoard(A3)
00000
00100
00100
00100
00000
and so on... .

注意，next_life_generation（A）返回一个新的板，所以我可以继续将A重新绑定到每一代 到目前为止，这是我的代码：

def countNeighbors(row, col, A):
count = 0
for row in range(len(A) - 1, len(A) + 2):
    for col in range(len(A) - 1, len(A) + 2):
        if A[row][col] == 1:
            count += 1
return count

def next_life_generation(A):
    for row in range(1, len(A) - 1):
        for col in range(1, len(A[0]) - 1):
            if A[row][col] == 0 and countNeighbors(row, col, A) == 3:
                A[row][col] = 1
            if countNeighbors(row, col, A) < 2:
                A[row][col] = 0
            elif countNeighbors(row, col, A) > 3:
                A[row][col] = 0
    return A

我的问题是我得到了这个错误：

    Traceback (most recent call last):
  File "<pyshell#10>", line 1, in <module>
    A = next_life_generation(A)
  line 88, in next_life_generation
    if countNeighbors(row, col, A) < 2:
  line 79, in countNeighbors
    if A[row][col] == 1:
IndexError: list index out of range

如果有人能帮助我，我将不胜感激！