Simple implementation of Burrows-Wheeler transformation in python

py-bwt.py

def encode(inputStr):
	rotations = [inputStr[i:] + inputStr[:i] for i in range(len(inputStr))]
	rotations.sort()
	encodedStr = [x[-1] for x in rotations]
	index = rotations.index(inputStr)
	return (''.join(encodedStr), index)

def decode(encodedStr, index):
	rotations = [encodedStr[i] for i in range(len(encodedStr))]
	for i in range(len(encodedStr) - 1):
		rotations.sort(key = lambda x : x[0])
		rotations = [encodedStr[i] + x for i,x in enumerate(rotations)]
	rotations.sort(key = lambda x : x[0])
	return rotations[index]

encode('damiankao') #outputs 'dikomnaaa' and 3
decode('dikomnaaa',3) #outputs 'damiankao'