lg.py

	# in one or both list.
	for (label, value) in allLabels:
		if label in llist1.keys() and \
				label in llist2.keys():
			llist1[ label ] = \
				combfn( llist1[label], weight1,\
						llist2[label], weight2 )
		elif label in llist2.keys():
			llist1[ label ] = \
				weight2 * llist2[label]
		else:
			llist1[ label ] = \
				weight1 * llist1[label]


def mergeMaps(map1, weight1, map2, weight2, combfn):
	"""Combine values in two maps according to the passed combfn
	function, and passed weights for each map."""
	# Odds are good that there are built-in function for this
	# operation.
	objects1 = map1.keys()
	objects2 = map2.keys()
	allObjects = set(objects1).union(set(objects2))
	for object in allObjects:
		if object in objects1 and object in objects2:
			# Combine values for each label in lg2 already in self.
			mergeLabelLists(map1[object],weight1, map2[object], weight2, combfn )			
		# DEBUG: no relationship ('missing') edges should
		# be taken as certain (value 1.0 * weight) where not explicit.
		elif object in objects2:
			# Use copy to avoid aliasing problems.
			# Use appropriate weight to update value.
			map1[ object ] = copy.deepcopy( map2[ object ] )
			for (label, value) in map1[object].items():
				map1[object][label] = weight2 * value
			map1[object]['_'] = weight1 
		else:
			# Only in current map: weight value appropriately.
			for (label, value) in map1[object].items():
				map1[object][label] = weight1 * value
			map1[object]['_'] = weight2