List 列表索引超出范围？不应该这样

代码正在生成以下错误

def trav(r,c):
  #print("(",r,",",c,")")
  ch = a[r+1][c+1]

  lu= a[r][c]
  #print(lu)
  u = a[r][c+1]
  #print(u)
  ru= a[r][c+2]
  #print(ru)

  l = a[r+1][c]
  #print(l)
  r = a[r+1][c+2]
  #print(r)

  ld= a[r+2][c]
  #print(ld)
  d = a[r+2][c+1]
  #print(d)
  rd= a[r+2][c+2]
  #print(rd)

  a1 = a2 = a3 = a4 = a5 = a6 = a7 = a8 = 0

  if(ch == lu-1):
    a1 = trav(r-1,c-1)

  if(ch == u-1):
    a2 = trav(r-1,c)

  if(ch == ru-1):
    a3 = trav(r-1,c+1)

  if(ch == l-1):
    a4 = trav(r,c-1)

  if(ch == r-1):
    a5 = trav(r,c+1)

  if(ch == ld-1):
    a6 = trav(r+1,c-1)

  if(ch == d-1):
    a7 = trav(r+1,c)

  if(ch == rd-1):
    a8 = trav(r+1,c+1)

  return max(a1,a2,a3,a4,a5,a6,a7,a8) + 1


while(1):
  row,col = [int(x) for x in input().split(" ")]

  if(row == 0):
    break

  a = []
  for index in range(10):
    a.append([])
    for jindex in range(10):
      a[index].append('a')

  b = []
  for index in range(row):
    str = input()
    for jindex in range(col):
      a[index+1][jindex + 1] = ord(str[jindex])
      if(str[jindex] == 'A'):
        b.append([index,jindex])

  #print (a)
  #print (b)

  ans = max([trav(x[0],x[1]) for x in b])

  print(ans)

它必须打破

r=a[r+1][c+2]

---

您正在该行中重新分配“r”的值。还请注意，您不应该将字符串命名为“str”，因为它是python字符串模块的名称，您将无法使用它。

声明了

a

在哪里？+1：您在我之前就知道了。在此行之前，

r

和

c

都等于0，并且该语句中

a[1][2]

的值为

66

。

a

中只有10个列表，因此索引将不可避免地超出范围。如果不知道代码的目的是什么，我们都很难说出这一行应该是什么。。。此时，该值将始终超出范围：该行捕获字符的ord，它将始终大于硬编码范围10.ohh！哎呀！谢谢你，伙计！谢谢！根本就不会看到它！

 Traceback (most recent call last):   File "C:/Users/DELL/Desktop/ABCPATH.py", line 80, in <module>
    ans = max([trav(x[0],x[1]) for x in b])   File "C:/Users/DELL/Desktop/ABCPATH.py", line 80, in <listcomp>
    ans = max([trav(x[0],x[1]) for x in b])   File "C:/Users/DELL/Desktop/ABCPATH.py", line 17, in trav
    ld= a[r+2][c] IndexError: list index out of range

4 3
ABC
CFG
BDH
ABC