diff --git a/tools/common.py b/tools/common.py
index e07fe9331b7fbd19a85616ecc0a5e51939903cee..b708fc505e2b6de12f118346cda3e39a54ee9905 100644
--- a/tools/common.py
+++ b/tools/common.py
@@ -44,5 +44,7 @@ class CaffeEnvType(enum.Enum):
 # common functions
 ################################
 def formatted_file_name(input_file_name, input_name):
-    return input_file_name + '_' + \
-           re.sub('[^0-9a-zA-Z]+', '_', input_name)
+    res = input_file_name + '_'
+    for c in input_name:
+        res += c if c.isalnum() else '_'
+    return res
diff --git a/tools/generate_data.py b/tools/generate_data.py
index 668838bcde7d965d5a6fd91969c8447568b0731d..747f0c232334dd02fed4ca07f2fcaffafbb8d458 100644
--- a/tools/generate_data.py
+++ b/tools/generate_data.py
@@ -16,6 +16,7 @@ import argparse
 import sys
 import numpy as np
 import re
+import common
 
 # Validation Flow:
 # 1. Generate input data
@@ -29,8 +30,7 @@ import re
 def generate_data(name, shape, input_file):
     np.random.seed()
     data = np.random.random(shape) * 2 - 1
-    input_file_name = input_file + "_" + re.sub('[^0-9a-zA-Z]+', '_',
-                                                name)
+    input_file_name = common.formatted_file_name(input_file, name)
     print 'Generate input file: ', input_file_name
     data.astype(np.float32).tofile(input_file_name)