flashing 'flash' messages in flask

flask_flash.html

{% for message in get_flashed_messages() %}
<div class="alert alert-warning alert-dismissible" role="alert">
    <button type="button" class="close" data-dismiss="alert" aria-label="Close"
    <span
            aria-hidden="true">&times;</span></button>
    {{ message }}
</div>
{% endfor %}