Creates the list of environments to read

    :param obj: the settings instance
    :param env: settings env default='DYNACONF'
    :return: a list of working environments

def _get_env_list(obj, env):
    """Creates the list of environments to read

    :param obj: the settings instance
    :param env: settings env default='DYNACONF'
    :return: a list of working environments
    """
    # add the [default] env
    env_list = [obj.get("DEFAULT_ENV_FOR_DYNACONF")]
    # compatibility with older versions that still uses [dynaconf] as
    # [default] env
    global_env = obj.get("ENVVAR_PREFIX_FOR_DYNACONF") or "DYNACONF"
    if global_env not in env_list:
        env_list.append(global_env)
    # add the current env
    if obj.current_env and obj.current_env not in env_list:
        env_list.append(obj.current_env)
    # add a manually set env
    if env and env not in env_list:
        env_list.append(env)
    # add the [global] env
    env_list.append("GLOBAL")
    return [env.lower() for env in env_list]