Set hparams overrides from unparsed args list.

def set_hparams_from_args(args):
  """Set hparams overrides from unparsed args list."""
  if not args:
    return

  hp_prefix = "--hp_"
  tf.logging.info("Found unparsed command-line arguments. Checking if any "
                  "start with %s and interpreting those as hparams "
                  "settings.", hp_prefix)

  pairs = []
  i = 0
  while i < len(args):
    arg = args[i]
    if arg.startswith(hp_prefix):
      pairs.append((arg[len(hp_prefix):], args[i+1]))
      i += 2
    else:
      tf.logging.warn("Found unknown flag: %s", arg)
      i += 1

  as_hparams = ",".join(["%s=%s" % (key, val) for key, val in pairs])
  if FLAGS.hparams:
    as_hparams = "," + as_hparams
  FLAGS.hparams += as_hparams