diff --git a/tools/CrossStackProfiler/CspFileReader.py b/tools/CrossStackProfiler/CspFileReader.py
index 475da769936a772dd98f7a5fda663cabb7091eb6..32281013ab68dc0b0541884259ebb7a375f1184e 100755
--- a/tools/CrossStackProfiler/CspFileReader.py
+++ b/tools/CrossStackProfiler/CspFileReader.py
@@ -178,6 +178,7 @@ class FileReader(object):
             if (self._getId(self._fileList[-1]) -
                     self._getId(self._fileList[0])) != len(self._fileList) - 1:
                 raise Exception("The file id should be countious!")
+
         # sort
         def _sortBySuffix(elem):
             return int(elem.split(".")[-1])