code: def sortForSameExpTime(expTimes, img_paths):
      '''
      return image paths sorted for same exposure time
      '''
      d = {}
      for e, i in zip(expTimes, img_paths):
          if e not in d:
              d[e] = []
          d[e].append(i)
      d = OrderedDict(sorted(d.items()))
      return list(d.keys()), list(d.values())