old_contents: 
  from sys import argv
  from os.path import exists
  
  script, from_file, to_file = argv
  
  print "Copying from %s to %s." % (from_file, to_file)
  
  in_file = open(from_file)
  indata = in_file.read()
  
  print "The input file is %d bytes long" % len(indata)
  
  print "Does the outpus file exist? %r" % exists(to_file)
  print "Ready? hit RETURN to continue, CTRL-C to abort."
  raw_input()
  
  out_file = open(to_file, 'w')
  out_file.write(indata)
  
  print "All done!"
  
  out_file.close()
  in_file.close()
  
new_contents: 
  from sys import argv
  from os.path import exists
  
  script, from_file, to_file = argv
  
  print "Copying from %s to %s." % (from_file, to_file)
  
  indata = open(from_file).read()
  
  print "The input file is %d bytes long" % len(indata)
  
  print "Does the output file exist? %r" % exists(to_file)
  print "Ready? hit RETURN to continue, CTRL-C to abort."
  raw_input()
  
  out_file = open(to_file, 'w')
  out_file.write(indata)
  
  print "All done!"
  
  out_file.close()
  
subject: change ex17.py file read to only one line