Using revised tempfile module

[Edward C. Jones]

#! /usr/bin/env python

import os, tempfile

# I have written code like this several times. It uses the deprecated
# function tempfile.mktemp. How do I write this with the new tempfile
# functions?

def do_something(filename1, filename2):
     os.system('cat %s > %s' % (filename1, filename2))

filename1 = tempfile.mktemp()
filename2 = tempfile.mktemp()
try:
     f = file(filename1, 'w')
     f.write('abcd')
     f.close()
     do_something(filename1, filename2)
     g = file(filename2, 'r')
     print g.read()
     g.close()
finally:
     if os.path.exists(filename1):
         os.remove(filename1)
     if os.path.exists(filename2):
         os.remove(filename2)