details about coded lines

hello, i have used the code lines below to make loops using a counter.

However i would like to know what does the line 1, line 2,line 3, line 4 and line 5 do in order that i can understand well ?

Can someone help please ?

import time

count = 1 --line1

for i in range(3):
    print "This is run number %s"%(count) --line2
    a = time.clock()

    doubleClick() /* scenario starts
    wait(1)
    hover()
    sleep(2)
    click()
    sleep(2)
    hover()
    click() */ scenario ends

    print " Run time: ",time.clock()-a,"seconds" --line3
    print "____________________________" --line 4

    count +=1 --line 5

thanks