flask form errors

gistfile1.txt

 {% if form.errors %}
                <div class="alert alert-danger">
                    <ul>
                    {% for field_name, field_errors in form.errors|dictsort if field_errors %}
                        {% for error in field_errors %}
                            <li>{{ form[field_name].label }}: {{ error }}</li>
                        {% endfor %}
                    {% endfor %}
                    </ul>
                </div>
            {% endif %}