spark in python inspired by http://news.ycombinator.com/item?id=3237478 and https://gist.github.com/1366875

spark.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

BARS = u'▁▂▃▅▆▇'

import sys

data = sys.argv[1:] or sys.stdin.read().split()
data = (x.strip() for x in data)
data = [float(x) for x in data if x]
incr = min(data)
width = (max(data) - min(data)) / (len(BARS) - 1)
bins = [i*width+incr for i in range(len(BARS))]
indexes = [i for n in data
           for i, thres in enumerate(bins)
           if thres <= n < thres+width]
print ''.join(BARS[i] for i in indexes)