def verify_email_validator(form, values):
    if values['email_address'] != values['verify_email']:
        raise Invalid(form, 'Email values do not match')


class MySchema(MappingSchema):

    def __init__(self, *args, **kwargs):
        super(KickEntrySchema, self).__init__(*args, **kwargs)
self.validator = verify_email_validator
email_address = SchemaNode(Email())
verify_email = SchemaNode(Email())
Валидатор Deform/Colander, который имеет доступ ко всем узлам?