twisted.py 文件源码

def makeDeferredWithProcessProtocol():
    """Returns a (`Deferred`, `ProcessProtocol`) tuple.

    The Deferred's `callback()` will be called (with None) if the
    `ProcessProtocol` is called back indicating that no error occurred.
    Its `errback()` will be called with the `Failure` reason otherwise.
    """
    done = Deferred()
    protocol = ProcessProtocol()
    # Call the errback if the "failure" object indicates a non-zero exit.
    protocol.processEnded = lambda reason: (
        done.errback(reason) if (reason and not reason.check(ProcessDone))
        else done.callback(None))
    return done, protocol