code: def spark_string(ints):
      
      ticks = u'▁▂▃▅▆▇'
      ints = [i for i in ints if type(i) == int]
      if len(ints) == 0:
          return ""
      step = (max(ints) / float(len(ticks) - 1)) or 1
      return u''.join(
          ticks[int(round(i / step))] if type(i) == int else u'.' for i in ints)
docs: Returns a spark string from given iterable of ints.