Python Flask Dependent Dropdown

[Anfaa]

Hello,
we would much rather see if you explained the problem here, as well as post the code in Python code tags. Thanks.

Sure no problem:

I was wondering if someone could help me.

I want to be able to click on customer and locations be based off of the certain customer, being a dependent dropdown. This information is coming from a database, hence the queries in the following code.

This is my form function for both customer and location

class CustomerPick(SubForm):
        customer = QuerySelectField(u'Customer',
                            get_label=u'sCustomer',
                            query_factory=lambda : 
                            (TCustomer.query.order_by(TCustomer.sCustomer)),
                            validators=[DataRequired(),])
        location = QuerySelectField(u'Location',
                            get_label=u'sLocation',
                            query_factory=lambda : 
                            (TLocation.query.order_by(TLocation.sLocation)),
                            validators=[DataRequired(),])

Here is the view portion

@route('new/', methods=['GET', 'POST'])
    def new(self):
        form = CustomerPick()
        if form.validate_on_submit():

This is a picture of the dropdown also for reference, if there is anything else needed for you guys to have a go please let me know. Thanks in advance! https://i.stack.imgur.com/Nzf5J.png