new_contents: #!/usr/bin/env python
  
  # Exercise 16: Reading and Writing Files
  
  from sys import argv
  
  script, filename = argv
  
  print "We're going to erase %r." % filename
  print "If you don't want that, hit CTRL-C (^C)."
  print "If you do want that, hit RETURN."
  
  raw_input("?")
  
  print "Opening the file..."
  target = open(filename, 'w')
  
  print "Truncating the file.  Goodbye!"
  target.truncate()
  
  print "Now I'm going to ask you for three lines."
  
  line1 = raw_input("line 1: ")
  line2 = raw_input("line 2: ")
  line3 = raw_input("line 3: ")
  
  print "I'm going to write these to the file."
  
  target.write(line1)
  target.write("\n")
  target.write(line2)
  target.write("\n")
  target.write(line3)
  target.write("\n")
  
  print "And finally, we close it."
  target.close()
  
subject: add ex16