文本文件編輯和行寫

Question

我的代碼有一個小問題。

首先是代碼：

import os
import subprocess
import httplib, urllib

for ip in range(1,255):

   ip_addr = "192.168.1." + str(ip)
   res = subprocess.call(["ping", ip_addr, "-c1", "-W1", "-q"], stdout=open(os.devnull,'w'))
   if res == 0:
      print (ip_addr) + " reachable"
   else:
      print (ip_addr) + " not reachable"

   f = open('state_All.txt','r')
   prestate = f.readline(ip)
   f.close()
   prestate = ord(prestate)
   res = res + 97
   if not prestate == res:
      if prestate == 97:
         conn = httplib.HTTPSConnection("api.pushover.net:443")
         ## The Code in here which I have deleted out is definitely not the problem,
         ## works 100% safe and can't be share beacuse of security problems.
          }), { "Content-type": "application/x-www-form-urlencoded" })
         conn.getresponse()
      else:
         conn = httplib.HTTPSConnection("api.pushover.net:443")
         ## The Code in here which I have deleted out is definitely not the problem,
         ## works 100% safe and can't be share beacuse of security problems.
          }), { "Content-type": "application/x-www-form-urlencoded" })
         conn.getresponse()
   f = open('state_All.txt','w')
   res = str(unichr(res))
   data = (res[ip])
   f.writelines(data)
   f.close()

問題：

讀取.txt文件中的某些特定行有效，但此后我無法在特定行中寫入測量狀態，

我收到此錯誤：

Traceback (most recent call last):
  File "ping_All.py", line 48, in <module>
    data = (res[ip])
IndexError: string index out of range

希望有人可以幫助我。

Answer 1

當您嘗試從該字符串訪問項目時， index out of range 。 這意味着您嘗試訪問索引（ ip ）大於res長度或小於0的項目（以您的情況為Character）。