Merge pull request #17 from MHenderson/16-docs-and-tests

Add docs and tests for both functions

src/vizing/__init__.py

@@ -1,15 +1,27 @@
 import constraint
 
-def list_colouring_problem(G):
+def node_list_colouring_problem(G):
+  """
+  Return a constraint problem representing a node list-colouring instance.
+
+  :param G: A graph with lists of permissible colours assigned to nodes.
+  :return A node list-colouring constraint problem.
+  """
   P = constraint.Problem()
   for node in G.nodes():
     P.addVariable(node, G.nodes[node]['permissible'])
   for edge in G.edges():
     P.addConstraint(constraint.AllDifferentConstraint(), edge)
   return(P)
 
-def list_colouring_solution(G):
-  P = list_colouring_problem(G)
+def node_list_colouring_solution(G):
+  """
+  Return a list-coloured graph.
+
+  :param G: A graph with lists of permissible colours assigned to nodes.
+  :return A properly list-coloured graph.
+  """
+  P = node_list_colouring_problem(G)
   S = P.getSolution()
   for node in S:
     G.nodes[node]['colour'] = S[node]

tests/test_node_list-colouring.py

@@ -0,0 +1,17 @@
+import listcolouring
+import networkx as nx
+import vizing
+
+def test_node_list_colouring_problem():
+  G = nx.petersen_graph()
+  G = listcolouring.list_init_node(G, range(1, 10), 3, 0)
+  G = vizing.node_list_colouring_problem(G)
+
+def test_node_list_colouring_solution():
+  G = nx.complete_graph(3)
+  permissible_dict = {0: [0, 1], 1: [1, 2], 2: [2, 3]}
+  nx.set_node_attributes(G, permissible_dict, "permissible")
+  G = vizing.node_list_colouring_solution(G)
+  assert G.nodes[0]['colour'] == 1
+  assert G.nodes[1]['colour'] == 2
+  assert G.nodes[2]['colour'] == 3