我有这个代码，假设要删除所有实体，但它所做的只是创建一个空实体
Class_data = Class_Name.query().fetch()
for classX in Class_data:
class_json_pre = json.dumps(classX)
class_json = json.loads(class_json_pre)
class_delete = Class_Name.get_by_id(class_json.class_name)
class_delete.delete()
像这样创建一个Class_Name
new_class = Class_Name(class_title = new_dictionary,class_name = classname, id = classname)