code: def _load_file(path):
      
      if not os.path.exists(path):
          parser.error("{} was not found!".format(path))
      if USING_PYTHON2:
          mode = "r"
      else:
          mode = "rb"
      try:
          f = open(path, mode)
          return f
      except IOError as ex:
          parser.error("{path} could not be read due to an I/O error! ({ex})".format(path=path, ex=ex))
docs: Loads a file from the local filesystem