diff --git a/cup/platforms.py b/cup/platforms.py
index 345f7b9..ed2e6c4 100644
--- a/cup/platforms.py
+++ b/cup/platforms.py
@@ -7,13 +7,16 @@
     cross-platform functions related module
 """
 
+import sys
 import select
 import platform
 
 __all__ = [
     'is_linux',
     'is_windows',
-    'is_mac'
+    'is_mac',
+    'is_py2',
+    'is_py3'
 ]
 
 
@@ -54,4 +57,22 @@ def is_mac():
         return False
 
 
+def is_py2():
+    """
+    is python 2.x
+    """
+    if sys.version_info >= (3, 0):
+        return False
+    if sys.version_info < (3, 0):
+        return True
+    raise ValueError('cannot determine if it\'s python2')
+
+
+def is_py3():
+    """is python 3.x"""
+    if (3, 0) <= sys.version_info <= (4, 0):
+        return True
+    else:
+        return False
+
 # vi:set tw=0 ts=4 sw=4 nowrap fdm=indent
diff --git a/cup/shell/oper.py b/cup/shell/oper.py
index 044ddf1..a960265 100644
--- a/cup/shell/oper.py
+++ b/cup/shell/oper.py
@@ -24,9 +24,10 @@
 import subprocess
 
 import cup
-from cup import decorators
 from cup import err
 from cup import log
+from cup import platforms
+from cup import decorators
 
 
 # linux only import
@@ -518,6 +519,9 @@ def _signal_handle():
             signal.signal(signal.SIGPIPE, signal.SIG_DFL)
 
         def _trans_bytes(data):
+            """trans bytes into unicode for python3"""
+            if platforms.is_py2():
+                return data
             if isinstance(data, bytes):
                 try:
                     data = bytes.decode(data)
diff --git a/cup/version.py b/cup/version.py
index 81eddca..00cc021 100644
--- a/cup/version.py
+++ b/cup/version.py
@@ -13,7 +13,7 @@
 ]
 
 
-VERSION = '3.2.12'
+VERSION = '3.2.13'
 AUTHOR = 'CUP-DEV Team'
 
 # vi:set tw=0 ts=4 sw=4 nowrap fdm=indent