High CPU utilization with Pylab

[Madhur]

I am trying to plot a runtime graph using pylab. But the very purpose
of functionality is lost because of high CPU percentage hogged by
plotting the graph.

Here is the piece of code which I have written.

def timerfunc(ulcm, dlcm):
    count=0
    xaxis=[]
    yaxis=[]
    ion()
    while 1:
        xaxis.append(count)
        dr=(((dlcm.sum)/dlcm.timer)*8)
        dlcm.counter=0
        yaxis.append(dr)
        dlcm.sum=0
        h=plot(xaxis,yaxis,'b')
        draw()
        count=count+1
        time.sleep(dlcm.timer/1000.0)
        if (count>100):
           xlim(count-100, count)

Here is the function which plots the graph.

Is there something which does not makes sense .?

-Madhur