Measuring efficiency by time spent in finishing a program

The following program measures how much time, in seconds, is required to finish a program. The function used is time.clock():

import time
start = time.clock()
n=10000000
for i in range(1,n):
    k=i+i+2
diff= (time.clock() - start)
print round(diff,2)

The total time we need to finish the previous meaningless loop is about 1.59 seconds.