# https://stackoverflow.com/questions/1094841/get-human-readable-version-of-file-size
def sizeof_fmt(num, suffix='B'):
	if num is None:
		return ''
	for unit in ['','Ki','Mi','Gi','Ti','Pi','Ei','Zi']:
		if abs(num) < 1024.0:
			return "%3.1f%s%s" % (num, unit, suffix)
		num /= 1024.0
	return "%.1f%s%s" % (num, 'Yi', suffix)