text: import sys, os
  
  #pylint: disable=E0602
  sys.path.append(os.getcwd())
  from importQt import *
  
  class SliderDemo(QWidget):
      def __init__(self):
          super().__init__()
          self.setWindowTitle("Slider Demo")
  
          layout = QVBoxLayout()
          self.label = QLabel("Hello PyQt5")
          self.label.setFont(QFont("Arial", 20))
          self.label.setAlignment(Qt.AlignCenter)
          layout.addWidget(self.label)
  
          self.slider = QSlider(Qt.Horizontal)
          self.slider.setMaximum(50)
          self.slider.setMinimum(10)
          self.slider.setSingleStep(3)
          self.slider.setValue(20)
          self.slider.setTickPosition(QSlider.TicksBelow)
          self.slider.setTickInterval(5)
          layout.addWidget(self.slider)
          self.slider.valueChanged.connect(self.valueChange)
  
          self.setLayout(layout)
      
      def valueChange(self):
          print("Current slider value = %s" % self.slider.value())
          size = self.slider.value()
          self.label.setFont(QFont("Arial", size))
  
  if __name__ == '__main__':
      app = QApplication(sys.argv)
      demo = SliderDemo()
      demo.show()
      sys.exit(app.exec())
  
  