python - 扭曲的 python : the correct way to pass a kwarg through the component system to a factory

Question

我需要使用 super 将 kwarg 传递给与 FingerFactoryFromService 等效的父类。

我知道我实际上是将 kwarg 传递给 IFingerFactory，因为这也是我传递最终在 init FingerFactoryFromService 中的服务的地方，我可以理解它在组件系统中的某个地方被绊倒了但我想不出其他办法。

我不断收到的错误是

exceptions.TypeError: 'test' is an invalid keyword argument for this function

我的 virtualenv 中的代码版本是:

pip (1.4.1)
setuptools (1.1.6)
Twisted (13.1.0)
wsgiref (0.1.2)
zope.interface (4.0.5)

这是手指教程中演示该问题的简化示例:

from twisted.protocols import basic

from twisted.application import internet, service
from twisted.internet import protocol, reactor, defer
from twisted.python import components
from zope.interface import Interface, implements  # @UnresolvedImport


class IFingerService(Interface):

    def getUser(user):  # @NoSelf
        """
        Return a deferred returning a string.
        """

    def getUsers():  # @NoSelf
        """
        Return a deferred returning a list of strings.
        """


class IFingerFactory(Interface):

    def getUser(user):  # @NoSelf
        """
        Return a deferred returning a string.
        """

    def buildProtocol(addr):  # @NoSelf
        """
        Return a protocol returning a string.
        """


def catchError(err):
    return "Internal error in server"


class FingerProtocol(basic.LineReceiver):

    def lineReceived(self, user):
        d = self.factory.getUser(user)
        d.addErrback(catchError)

        def writeValue(value):
            self.transport.write(value + '\r\n')
            self.transport.loseConnection()
        d.addCallback(writeValue)


class FingerService(service.Service):

    implements(IFingerService)

    def __init__(self, filename):
        self.filename = filename
        self.users = {}

    def _read(self):
        self.users.clear()
        for line in file(self.filename):
            user, status = line.split(':', 1)
            user = user.strip()
            status = status.strip()
            self.users[user] = status
        self.call = reactor.callLater(30, self._read)  # @UndefinedVariable

    def getUser(self, user):
        print user
        return defer.succeed(self.users.get(user, "No such user"))

    def getUsers(self):
        return defer.succeed(self.users.keys())

    def startService(self):
        self._read()
        service.Service.startService(self)

    def stopService(self):
        service.Service.stopService(self)
        self.call.cancel()


class FingerFactoryFromService(protocol.ServerFactory):

    implements(IFingerFactory)

    protocol = FingerProtocol

    #def __init__(self, srv):
    def __init__(self, srv, test=None):
        self.service = srv
        ## I need to call super here because my equivalent of ServerFactory requires 
        ## a kwarg but this cutdown example doesnt so I just assign it to a property
        # super(FingerFactoryFromService, self).__init__(test=test)
        self.test_thing = test or 'Default Something'

    def getUser(self, user):
        return self.service.getUser(user)

components.registerAdapter(FingerFactoryFromService,
                           IFingerService,
                           IFingerFactory)

application = service.Application('finger')
serviceCollection = service.IServiceCollection(application)

finger_service = FingerService('/etc/passwd')
finger_service.setServiceParent(serviceCollection)

#line_finger_factory = IFingerFactory(finger_service)
line_finger_factory = IFingerFactory(finger_service, test='Something')
line_finger_server = internet.TCPServer(1079, line_finger_factory)
line_finger_server.setServiceParent(serviceCollection)  

Answer 1

这与组件系统无关。您想要做的是重写 Factory 的 buildProtocol 方法，如下所示:

https://twistedmatrix.com/documents/current/core/howto/servers.html#auto9