Python-сообщество

 class MyWindow(QtWidgets.QWidget):
    def __init__(self,parent=None):
        QtWidgets.QWidget.__init__(self,parent)
        self.resize(200,300)
        self.label = QtWidgets.QLabel(str(0),parent=self)
        self.label.move(50,50)
        self.label.setAlignment(QtCore.Qt.AlignCenter)
        self.label.show()
        self.button = QtWidgets.QPushButton("Начать скан", self)
        self.button.setStyleSheet('background:green;color:white;')
        self.button.clicked.connect(self.ter)
   def ter(self):       
        for w in range(0,10):
            self.label.setText(str(w))
            self.label.update()
            time.sleep(0.4)
            print(w)
if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv) 
    window = MyWindow()
    window.show()
    sys.exit(app.exec_())