#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ def getReverseConnectivity(connectivity): """getReverseConnectivity(connectivity) --> resort connectivity dict with nodes as keys""" reverseConnectivity = {} for el, conn in connectivity.items(): for node in conn: if node not in reverseConnectivity.keys(): reverseConnectivity[node]=[el,] else: reverseConnectivity[node].append(el) return reverseConnectivity >>> sc = {70: [156, 159, 158, 155], 69: [155, 158, 157, 154], 68: [153, 156, 155, 152], 67: [152, 155, 154, 151]} >>> getReverseConnectivity(sc) {159: [70], 158: [70, 69], 157: [69], 156: [70, 68], 155: [70, 69, 68, 67], 154: [69, 67], 153: [68], 152: [68, 67], 151: [67]}