text: from sys import argv
  script, input_file = argv
  def print_all(f):
      print(f.read())
  def rewind(f):
      f.seek(0)
  def print_a_line(line_count, f):
      print(line_count, f.readline())
  current_file = open(input_file)
  print("First let's print the whole file:\n")
  print_all(current_file)
  print("Now let's rewind, kind of like a tape.")
  rewind(current_file)
  print("Let's print three lines:")
  current_line = 1
  print_a_line(current_line, current_file)
  current_line = current_line + 1
  print_a_line(current_line, current_file)
  current_line = current_line + 1
  print_a_line(current_line, current_file)
  