How do I pre-select specific values from a dynamically populated dropdown list for HTML form?

{% for fetchcol in db_col %}

    {{ fetchcol }}
    

        {% for ex_col in df_list %}
            {% if ex_col == smart_mapping_dict[fetchcol] %}
                {{ ex_col }}
            {% else %}
                {{ ex_col }}
            {% endif %}
        {% endfor %}

    
    

    {% endfor %}

    

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