how to store phone_number fields in Flask model

class TelephoneForm(Form):
    country_code = IntegerField('Country Code', [validators.required()])
    area_code    = IntegerField('Area Code/Exchange', [validators.required()])
    number       = StringField('Number')

class ContactForm(Form):
    first_name   = StringField()
    last_name    = StringField()
    mobile_phone = FormField(TelephoneForm)
    office_phone = FormField(TelephoneForm)