干得好：
def clone_entity(e, **extra_args): """Clones an entity, adding or overriding constructor attributes. The cloned entity will have exactly the same property values as the original entity, except where overridden. By default it will have no parent entity or key name, unless supplied. Args: e: The entity to clone extra_args: Keyword arguments to override from the cloned entity and pass to the constructor. Returns: A cloned, possibly modified, copy of entity e. """ klass = e.__class__ props = dict((k, v.__get__(e, klass)) for k, v in klass.properties().iteritems()) props.update(extra_args) return klass(**props)
用法示例：
b = clone_entity(a)c = clone_entity(a, key_name='foo')d = clone_entity(a, parent=a.key().parent())
编辑：如果使用NDB更改
将Gus的以下注释与对指定不同数据存储名称的属性的修复结合起来，以下代码可用于NDB：
def clone_entity(e, **extra_args): klass = e.__class__ props = dict((v._pre_name, v.__get__(e, klass)) for v in klass._properties.itervalues() if type(v) is not ndb.ComputedProperty) props.update(extra_args) return klass(**props)
用法示例（注释在NDB中
key_name变为
id）：
b = clone_entity(a, id='new_id_here')
旁注：请参阅的使用，
_pre_name以获取Python友好的属性名称。如果没有此属性，则类似的属性
name =ndb.StringProperty('n')将导致模型构造函数引发AttributeError: type object 'foo' has noattribute 'n'。
