h column.
    if not hasattr(elt.data, "order"):
        elt.data.order = [0 for _ in elt.data.fields]

    order = elt.data.order[column]

    key = lambda x: x[column]

    # Changing the value of attribute "countries" will trigger re-rendering
    # the template
    elt.data.countries.sort(key=key, reverse=order)

    # next time, sort this column the other way
    elt.data.order[column] = 1 - order

fields = ["Nom", "Capitale", "Population", "Superficie", "Densité / km²"]

countries = [
    ['Albanie'