Preserve order of nodes

monitoring/db/scripts/get_detailed_power.py

@@ -43,21 +43,19 @@ class Power:
 		Returns a Power instance from a list of tuples (timestamp, node, value).
 
 		Assumptions:
-		 - data is sorted by timestamp first, then by node. Both ascending.
-		 - for each timestamp, there is the same set of nodes.
+		 - data is sorted by timestamp ascending
+		 - for each timestamp, there is the same set of nodes and in the same order
 		"""
 
 		idx_ts = 0; idx_node = 1; idx_value = 2
-		nodes = list(set([line[idx_node] for line in data]))
+		nodes = list(OrderedDict.fromkeys([line[idx_node] for line in data]))   # preserves order of nodes
 		cls = Power(nodes)
 
-		# for now ignore order to nodes
 		values = {}
 		for l in data:
 			ts = l[idx_ts]
 			if ts not in values:
 				values[ts] = []
-			# node = l[1]
 			power = l[idx_value]
 			values[ts].append(power)