modified pythonrc to make python version clear

pythonrc

@@ -15,4 +15,12 @@ def write_history(readline=readline, histfile=histfile):
         pass
 atexit.register(write_history)
 
+
+if sys.version_info.major == 3:
+    sys.ps1 = "3>>> "
+    sys.ps2 = "3... "
+else:
+    sys.ps1 = "2>>> "
+    sys.ps2 = "2... "
+
 del readline, histfile, atexit, write_history, sys, os