docs: def parse_duration(duration):
      """ Parse and prettify duration from youtube duration format """
      duration_dict = re.search(DURATION_REGEX, duration).groupdict()
      converted_dict = {}
      # convert all values to ints, remove nones
      for a, x in duration_dict.iteritems():
          if x is not None:
              converted_dict[a] = int(NON_DECIMAL.sub('', x))
      return str(timedelta(**converted_dict))