diff --git a/binding/python/xdb/searcher.py b/binding/python/xdb/searcher.py
index eeb889c..c22e092 100644
--- a/binding/python/xdb/searcher.py
+++ b/binding/python/xdb/searcher.py
@@ -98,7 +98,7 @@ class Searcher(object):
     def read(self, offset: int, length: int):
         # check the content buffer first
         if self.c_buffer != None:
-            return self.c_buffer[offset, offset + length]
+            return self.c_buffer[offset:offset+length]
         
         # load the buffer from file
         self.__handle.seek(offset)