docs: def set_worst(old_worst, new_worst):
      """
      Pad new_worst with zeroes to prevent it being shorter than old_worst.
      
      >>> set_worst(311920, '48-49')
      '48-490'
      >>> set_worst(98, -2)
      -20
      """
      
      if isinstance(new_worst, bool):
          return new_worst
      # Negative numbers confuse the length calculation. 
      negative = ( (hasattr(old_worst, '__neg__') and old_worst < 0) or
                   (hasattr(new_worst, '__neg__') and new_worst < 0) )
      try:
          old_worst = abs(old_worst)
          new_worst = abs(new_worst)
      except TypeError:
          pass
     
      # now go by length 
      new_len = len(str(new_worst))
      old_len = len(str(old_worst))
      if new_len < old_len:
          new_type = type(new_worst)
          new_worst = str(new_worst).ljust(old_len, '0')
          new_worst = new_type(new_worst)
          
      # now put the removed negative back
      if negative:
          try:
              new_worst = -1 * abs(new_worst)
          except:
              pass
          
      return new_worst