Eu tenho uma situação onde eu preciso começar dois tópicos um após o outro. Eu tentei o trecho de código a seguir, aqui eu poderia capaz de iniciar o Thread12, mas não é capaz de iniciar Thread2. Como posso começar os dois ....? Como começar 2 tópicos um ofter o outro ...?

Fragmento de código

class Thread1(QtCore.QThread):

    Thread1Signal = QtCore.pyqtSignal(str)

    def __init__(self):
        super(Thread1, self).__init__()

    def run(self):
        print 'Thread1 started'
        While True:

            #some statments
            if Condition:
                Thread1Signal.emit('Yes')
            else:
                Thread1Signal.emit('No')

class Thread2(QtCore.QThread):

    Thread2Signal = QtCore.pyqtSignal(str)

    def __init__(self):
        super(Thread2, self).__init__()

    def run(self):
        print 'Thread2 started'
        While True:

            #some statments
            if Condition:
                Thread2Signal.emit('Yes')
            else:
                Thread2Signal.emit('No')

class MainClass(QtCore.QObject):

    MainSignal1 = QtCore.pyqtSignal(str)
    MainSignal2 = QtCore.pyqtSignal(str)

    def __init__(self):
        super(MainClass, self).__init__()   

        Threadinstance1 = Thread1()
        Threadinstance1.Thread1Signal.connect(MainSignal1)

        Threadinstance2 = Thread2()
        Threadinstance2.Thread2Signal.connect(MainSignal2)


   def start(self):

       Threadinstance1.start()
       Threadinstance2.start()                #Thread2 never starts.

def signal1called(s):

    print s


def signal2called(s):

    print s

if __name__=='__main__':
    app = AtGui.QApplication(sys.argv)
    temp = MainClass()
    temp.MainSignal1.connect(signal1called)
    temp.MainSignal2.connect(signal2called)
    temp.start()
    sys.exit(app.exec()_)