exchangeNames=["one","two","three"]
class addExchange_All(Form):

apis={}
secrets={}

for exchangeName in exchangesNames:

    apis[exchangeName+"_api"] = TextField(
                    description=('Enter %s Api Key:', exchangeName))

    secrets[exchangeName+'_secret'] = TextField(validators=[RequiredIf(exchangeName+'_api')],
                description=('Enter %s Api Key:', exchangeName))


submit = SubmitField('Update Exchange Credentials')

@account.route('/manage/exchanges', methods=['POST', 'GET'])
def exchanges():
    form=addExchange_All()
    return render_template('/account/exchanges.html', form=form)

<div class="two fields">

           {%for a in form.apis%}
           {{f.render_form_field(a)}}
           {%endfor%}
           {%for a in form.secrets%}
           {{f.render_form_field(a)}}
           {%endfor%}

        </div>

{# Render a field for the form #}
{% macro render_form_field(field, extra_classes='') %}
{% if field.type == 'Radio Field' %}
    {% set extra_classes = extra_classes + ' grouped fields' %}
{% endif %}
<div class="field {% if field.errors %}error{% endif %} {{
extra_classes }}">
    {{ render_form_input(field) }}
    {% if field.errors %}
        <div class="ui red pointing label">
            {{ field.errors[0] | safe }}
        </div>
    {% endif %}
</div>
{% endmacro %}