plotting data without plt.clear()

[omar_mohsen]

I am trying to use a matplotlib module in order to draw data coming from notepad the problem is that I must clear the data every time I parse data in order to plot the data by using plt.clear() now I want to have other alternatives as when I want to zoom in for the graph it returns automatically to the previous plotting which is annoying. The following is considered as a sample of the code

f = Figure(figsize=(5,5), dpi=100)
a = f.add_subplot(111)


def animate(i):
    pullData = open("sampleText.txt","r").read()
    dataList = pullData.split('\n')
    xList = []
    yList = []
    line,=plt.plot([],[])
    for eachLine in dataList:
        if len(eachLine) > 1:
            x, y = eachLine.split(',')
            xList.append(int(x))
            yList.append(int(y))
            line.set_data(xList,yList)
             
   

    a.clear()##the part that I want to have an alternative code for it
    a.plot(xList, yList)

Thanks for any help