Question

我正在用Python编写Google Appengine应用程序。该应用程序确实通过谷歌云端点消息接收和发送数据。您将在下面找到数据库模型定义的示例。 Object包含所有对象，ObjectBoolean只是布尔值，ObjectInteger只是整数对象。所有类都定义了两个方法：message_to_model（）和model_to_message（）。

如何重用子类中的方法？我想摆脱重复的代码，如：

        self.name = request.name
        self.description = request.description
        self.created = request.created
        self.modified = request.modified

这些字段是Object-class的一部分。但在我的代码中，字段也列在子类中，这是我想要避免的。我怎样才能做到这一点？我已经检查了super（）函数，但我认为这不适合我的情况，因为我不想执行我想扩展它的方法。

干杯

-Luca。

from google.appengine.ext.ndb import polymodel
from google.appengine.ext import ndb
from endpoint_messages.object import *


class Object(polymodel.PolyModel):
    name = ndb.StringProperty(required=True, verbose_name="Name")
    description = ndb.TextProperty(verbose_name="Description")
    created = ndb.DateTimeProperty(auto_now_add=True, verbose_name="Created")
    modified = ndb.DateTimeProperty(auto_now=True, verbose_name="Modified")

    def model_to_message(self):
        return ObjectResponseMessage(class_name=self._class_name(),
                                     id=self.key.integer_id(),
                                     name=self.name,
                                     description=self.description,
                                     created=self.created,
                                     modified=self.modified)

    def message_to_model(self, request):
        self.name = request.name
        self.description = request.description
        self.created = request.created
        self.modified = request.modified


class ObjectBoolean(Object):
    current = ndb.BooleanProperty(verbose_name="Current")
    target = ndb.BooleanProperty(verbose_name="Target")

    def model_to_message(self):
        return ObjectResponseMessage(class_name=self._class_name(),
                                     id=self.key.integer_id(),
                                     name=self.name,
                                     description=self.description,
                                     created=self.created,
                                     modified=self.modified,
                                     boolean=ObjectBooleanMessage(current=self.current,
                                                                  target=self.target))

    def message_to_model(self, request):
        self.name = request.name
        self.description = request.description
        self.created = request.created
        self.modified = request.modified
        if request.boolean:
            self.current = request.boolean.success
            self.target = request.boolean.target


class ObjectInteger(Object):
    current = ndb.IntegerProperty(verbose_name="Current")
    target = ndb.IntegerProperty(verbose_name="Target")

    def model_to_message(self):
        return ObjectResponseMessage(class_name=self._class_name(),
                                     id=self.key.integer_id(),
                                     name=self.name,
                                     description=self.description,
                                     created=self.created,
                                     modified=self.modified,
                                     float=ObjectIntegerMessage(current=self.current,
                                                                target=self.target))

    def message_to_model(self, request):
        self.name = request.name
        self.description = request.description
        self.created = request.created
        self.modified = request.modified
        if request.integer:
            self.current = request.integer.current
            self.target = request.integer.target

Answer 1

super()可用于此目的。你可以在ObjectBoolean：

中使用这样的东西

def message_to_model(self, request):
    super(ObjectBoolean, self).message_to_model(request)

    if request.boolean:
        self.current = request.boolean.success
        self.target = request.boolean.target

为了实现这一点，Object必须是一个新的样式类，如果polymodel.PolyModel是一个新的样式类，那就是它。

Python扩展父类的方法

1 个答案: