Reading in a file

[Maggie]

hello,

i have a basic script i need to implement. i need below code to read
in a file and perform operation is it designed to do:

#!/usr/bin/python

import sys

feed = sys.stdin.readlines()

for temp in feed:
  line = temp.split()
  if len(line) == 3:
     if (line[0] == "xmax" or line[0] == "xmin"):
       time = line[2]
       print str(line[0]) + " " + str(line[1]) + " " +
str(float(time)*2/3)
     else:
       print temp
  else:
     print temp

i appreciate your help in advance..