Install virtual environment for Python 3.3+; removing the old one if it exists

def install_virtualenv_p3(root, python_version):
    """ Install virtual environment for Python 3.3+; removing the old one if it exists """
    import venv
    builder = venv.EnvBuilder(system_site_packages=False, clear=True, symlinks=False, upgrade=False)
    builder.create(root)
    ret_code = subprocess.call([VE_SCRIPT, PROJECT_ROOT, root, python_version])
    sys.exit(ret_code)