modify registry in user environment

env_list = []
    new_env = 'D:\\Python27;D:\\Python27\\Scripts'
    user_env = _winreg.CreateKey(_winreg.HKEY_CURRENT_USER, 'Environment')

    try:
        value, type1 = _winreg.QueryValueEx(user_env, 'PATH')

        env_list = value.split(';')
        for env in env_list:
            if new_env == env:
                print 'exist'
                exit()
        temp_env = value + ';' + new_env
        print temp_env
    except:
        type1 = 1
        temp_env = new_env

        try:
            _winreg.SetValueEx(user_env, 'PATH', 0, type1, temp_env)
        except WindowsError as e:
            print e
        finally:
            _winreg.CloseKey(user_env)