我們在使用for迴圈的時候，由於python語言的高效性，致使我們漸漸忽略了一個很重要的角色，index。

      怎樣查詢當前記錄的下一條記錄呢？

   li1 = [3, 4, 5, 6, 7]
   i = 0
   for rec in li1:
       print "this record is: " + str(rec)
       if i + 1 < len(li1):
           print "next record is: " + str(li1[i + 1]       
       else:
           print "the last record!"
       print '\n'
       i += 1
 

this record is: 3
next record is: 4


this record is: 4
next record is: 5


this record is: 5
next record is: 6


this record is: 6
next record is: 7


this record is: 7
the last record!