def findHinges(rList0, rList1, segments):
	"""Find hinge residues, which are defined as the interface
	residues between segments that are at least 6 residues long."""
	segmentId = {}
	segId = 1
	for seg in segments:
		for r in seg[0]:
			segmentId[r] = segId
		segId += 1
	hingeIndices = []
	prevId = None
	prevCount = 0
	thisId = None
	thisCount = 0
	for rIndex, r in enumerate(rList0):
		newId = segmentId[r]
		if newId == thisId:
			thisCount += 1
		else:
			# Transition.  Check the previous two segment lengths
			# to see if we found a hinge; then move "this" to "prev"
			# and start a new segment.
			if prevCount >= 6 and thisCount >= 6:
				hingeIndices.append(rIndex - thisCount)
				prevCount = thisCount
			else:
				prevCount += thisCount
			thisCount = 1
			prevId = thisId
			thisId = newId
	if prevCount >= 6 and thisCount >= 6:
		hingeIndices.append(len(rList0) - thisCount)
	return hingeIndices

def splitOnHinges(hingeIndices, rList):
	"Split molecule into lists of consecutive residues at hinge residues"
	# Assumes that hinge indices are sorted
	if not hingeIndices:
		return [ rList ]
	else:
		start = 0
		segments = []
		for i in hingeIndices:
			segments.append(rList[start:i])
			start = i
		segments.append(rList[start:])
		return segments