zope.interface 库学习一

由于python没有接口概念，所以zope 提供了个第三方库开源使用，下面简单介绍zope.interface.implementer的使用

直接看例子，下面例子是在twisted里摘录的

接口IResolverSimple

class IResolverSimple(Interface):

    def getHostByName(name, timeout = (1, 3, 11, 45)):

        """

        Resolve the domain name C{name} into an IP address.

        """

实现BlockingResolver

@implementer(IResolverSimple)

class BlockingResolver:

    def getHostByName(self, name, timeout = (, , , )):

        try:

            address = socket.gethostbyname(name)

        except socket.error:

            msg = "address %r not found" % (name,)

            err = error.DNSLookupError(msg)

            return defer.fail(err)

        else:

            return defer.succeed(address)

可以通过

IResolverSimple.implementedBy

IResolverSimple.providedBy

对实现进行检测

foo = BlockingResolver()

IResolverSimple.implementedBy(BlockingResolver) #display True

IResolverSimple.implementedBy(foo) #display True