Switch between Python2 and Python3 on MS Windows cmd

py-ver.bat

@echo off
goto START

-------------------------------------------------------
 py-ver.bat

 set the PYTHON_HOME to version 2 or 3

 Created Sat May 11 13:00:00 2014

-------------------------------------------------------

:START
SETLOCAL ENABLEDELAYEDEXPANSION

if /i "%1"=="2" (
  echo Using python version %PYTHON2_HOME%
  set newPyPath=%PYTHON2_HOME%
  set oldPyPath=%PYTHON3_HOME%
) else (
  echo Using python version %PYTHON3_HOME%
  set newPyPath=%PYTHON3_HOME%
  set oldPyPath=%PYTHON2_HOME%
)

echo Replacing !oldPyPath! to !newPyPath! in PATH
call set newPath=%%PATH:!oldPyPath!=!newPyPath!%%

ENDLOCAL & set PATH=%newPath%

:FINISHED