def create_default_groups(self):
        for group in self.groups:
            group = group.replace(" ", "_").lower()
            self[group] = NamedRequirements(group)
def image_delete(filename):
    thumbnail_filepath = os.path.join(app.config.get('UPLOAD_FOLDER'), filename)
    filepath = thumbnail_filepath.replace('_thumbnail', '')
    os.remove(filepath)
    os.remove(thumbnail_filepath)