python - 为什么 zope.interface.Interface 的子类的子类不继承其父名称？

Question

例子:

>>> from zope.interface import Interface, Attribute
>>> class IA(Interface):
...   foo = Attribute("foo")
... 
>>> IA.names()
['foo']
>>> class IB(IA):
...   bar = Attribute("bar")
... 
>>> IB.names()
['bar']

如何让 IB.names() 也返回 IA 中定义的属性？

Answer 1

如果你看一下 zope.interface.interfaces module你会发现 Interface 类有一个 IInterface interface definition !它记录了 names 方法，如下所示:

def names(all=False):
    """Get the interface attribute names

    Return a sequence of the names of the attributes, including
    methods, included in the interface definition.

    Normally, only directly defined attributes are included. If
    a true positional or keyword argument is given, then
    attributes defined by base classes will be included.
    """

因此扩展您的示例:

>>> from zope.interface import Interface, Attribute
>>> class IA(Interface):
...     foo = Attribute("foo")
... 
>>> IA.names()
['foo']
>>> class IB(IA):
...     bar = Attribute("bar")
... 
>>> IB.names()
['bar']
>>> IB.names(all=True)
['foo', 'bar']