def showDifferences(seq1, seq2) :
	"""Returns a string highligthing differences between seq1 and seq2:
	
	* Matches by '-'
	
	* Differences : 'A|T'
	
	* Exceeded length : '#'
	
	"""
	ret = []
	for i in range(max(len(seq1), len(seq2))) :

		if i >= len(seq1) :
			c1 = '#'
		else :
			c1 = seq1[i]
		if i >= len(seq2) :
			c2 = '#'
		else :
			c2 = seq2[i]

		if c1 != c2 :
			ret.append('%s|%s' % (c1, c2))
		else :
			ret.append('-')

	return ''.join(ret)