Something

In [7]: class y(str):
   ...:     def __getslice__( self, start, end):
   ...:         print "0x%08x 0x%08x" % (start, end)
   ...:         
   ...:     def __getitem__(self, index):
   ...:         print "0x%08x" % index

In [8]: x = y()

In [10]: x[ 0x804dc340]
0x804dc340

In [14]: x[ 0x804dc34a:0x804dc34f]
0x7fffffff 0x7fffffff