Pyqt5:slider slider control

Slider There are generally two types of controls , Horizontal and vertical , Take the horizontal as an example

# Set max min 
self.horizontalSlider.setMaximum(80)      
self.horizontalSlider.setMinimum(10)

# Set single step value  
self.horizontalSlider.setSingleStep(2)

# Set initial value  
self.horizontalSlider.setValue(40)

# Set tick mark position         
self.horizontalSlider.setTickPosition(QSlider.TicksBelow)


# Set the signal and slot 
self.horizontalSlider.valueChanged.connect(self.value)


# The function of the slot is to use the slider to control a label font size 
def value(self):
    size = self.horizontalSlider.value()
    self.label_4.setFont(QFont('Arial', size))
    print(' The current value is ' + str(self.horizontalSlider.value()))