Parse str to tokens and pos tags.

def _get_tokens_and_tags(parse_str):
  """Parse str to tokens and pos tags."""
  tokens = []
  parse_split = parse_str.split(' ')
  for p in parse_split:
    assert p.startswith('(') or p.endswith(')')
    if p.endswith(')'):
      token = p.replace(')', '')
      tokens.append(token)

  return tokens