def test_undirected_graph_vertices_and_edges(self): """ Get undirected graphs' vertices and edges properties """ g = UndirectedGraph() g.add_vertex(v_val='v0') g.add_vertex(v_val='v1') g.add_edge(('v0', 'v1')) v0 = g.get_vertex('v0') v1 = g.get_vertex('v1') e01 = g.get_edge(('v0', 'v1')) self.assertEqual(set(g.vertices), set([v0, v1])) self.assertEqual(set(g.edges), set([e01])) with self.assertRaises(AttributeError): g.vertices = set() with self.assertRaises(AttributeError): g.edges = set()