pyqtgraph triaxial plot

plot.py

class TimeAxisItem(pg.AxisItem):
   def tickStrings(self, values, scale, spacing):
       return [datetime.fromtimestamp(value) for value in values]   
   

    
class PlotterDate():

    def __init__(self, data, starttime,size=(1280,720)):
        # Data stuff

        pg.setConfigOptions(antialias=True)
        self.t = starttime
        self.data=data
        # PyQtGraph stuff
        self.app = QtGui.QApplication([])
        self.view=pg.GraphicsView()  
        self.l=pg.GraphicsLayout() 
        self.l.layout.setSpacing(0.)                                                             
        self.l.setContentsMargins(0., 0., 0., 0.) 
        self.view.setCentralItem(self.l)
        self.view.show()
        self.view.resize(*size)
        self.vbs=[]
        self.line1=[]
        self.line2=[]
        self.date_axis = [TimeAxisItem(orientation='bottom'),\
                          TimeAxisItem(orientation='bottom'),\
                              TimeAxisItem(orientation='bottom')]
        self.plots=[]
        self.difference=[0,0,0]
        

        self.plotTexts=[]
        for i,v in enumerate (data):
            
            c=self.l.addPlot(i,0,axisItems = {'bottom': self.date_axis[i]})
            mytext='Difference in Plot {} is 0'.format(i+1)
            t=pg.TextItem(text=mytext,anchor=(-1,-10*i))
            l1=pg.InfiniteLine(0,angle=0,movable=True)
            l2=pg.InfiniteLine(0,angle=0,movable=True)
            self.view.addItem(t)
            c.addItem(l1)
            c.addItem(l2)

            l1.sigPositionChangeFinished.connect(self.getpos)
            l2.sigPositionChangeFinished.connect(self.getpos)
            
            
            c.showGrid(x = True, y = True, alpha = 0.5) 
            c.setLabel('left', 'CH{}'.format(i+1), '')
            c.disableAutoRange()
            stuff=c.plot([0],[0],pen=(i,3))
            self.line1.append(l1)
            self.line2.append(l2)
            self.plotTexts.append(t)
            if i>0:
                c.setXLink(self.vbs[0])
            self.plots.append(stuff)
            self.vbs.append(c)

        self.updateplot()
        
        for i in self.vbs:
            i.enableAutoRange()
            i.sigXRangeChanged.connect(self.setviewbox) 

            

        return
    
    def getpos(self,li):

        for i,v in enumerate(self.difference):
            self.difference[i]=abs(self.line1[i].value()-self.line2[i].value())
            text="Difference in Plot {} is {}".format(i+1,self.difference[i])
            self.plotTexts[i].setText(text)
        # print(*self.difference)
            
    def updateplot(self):
       for i,p in enumerate(self.plots):
           p.setData(self.t, self.data[i])
       return
   
    def setviewbox(self,vb):
        vb.disableAutoRange()
        vb.enableAutoRange(axis='y')
        vb.setAutoVisible(y=True)
        return