Python3 on Windows and virtual environments

the_python.py

# Credit goes to Mauro Riccardi (mauro.riccardi[at]gmail.com)
# You can read more about this on our blog: http://bitsentangled.com/2014/04/12/python3-on-windows-and-virtual-environments/

# script to register Python 2.0 or later for use with win32all
# and other extensions that require Python registry settings
#
# Adapted by Ned Batchelder from a script
# written by Joakim Low for Secret Labs AB / PythonWare
# Edited for Python3 compatibility by bitsentangled.com 
#
# source:
# http://www.pythonware.com/products/works/articles/regpy20.htm

import sys

try:
    from winreg import *
except ImportError:  #  python 2
    from _winreg import *

# tweak as necessary
version = sys.version[:3]
installpath = sys.prefix

regpath = "SOFTWARE\\Python\\Pythoncore\\%s\\" % (version)
installkey = "InstallPath"
pythonkey = "PythonPath"
pythonpath = "%s;%s\\Lib\\;%s\\DLLs\\" % (
installpath, installpath, installpath
)

def RegisterPy():
    try:
        reg = OpenKey(HKEY_LOCAL_MACHINE, regpath)
    except EnvironmentError:
        try:
            reg = CreateKey(HKEY_LOCAL_MACHINE, regpath)
        except Exception as e:
            print("*** Unable to register: %s" % (e,))
            return

    try:
        SetValue(reg, installkey, REG_SZ, installpath)
        SetValue(reg, pythonkey, REG_SZ, pythonpath)
        CloseKey(reg)
        print("--- Python %s at %s is now registered!" % (version, installpath))
    except PermissionError:
        print("Permission Error: please run the_python.py as administrator!")

if __name__ == "__main__":
    RegisterPy()