old_contents: import fileinput
  
  def read_code():
      return ''.join([line for line in fileinput.input()])
  
  if __name__ == '__main__':
      code = read_code()
      print(code)
  
new_contents: import fileinput
  
  def read_code(filename='-'):
      return ''.join([line for line in fileinput.input(filename)])
  
  if __name__ == '__main__':
      import sys
  
      filename = sys.argv[1] if len(sys.argv) > 1 else '-'
      code = read_code(filename)
      print(code)
  
subject: Correct a reading of a code