def test_predecessors(self):
graph = Graph({
"a": set(["b", "d"]),
"b": set(["a"]),
"c": set([]),
"d": set(["a"]),
"e": set([])
})
with self.assertRaises(NotDigraphError):
graph.predecessors("a")
def test_predecessors(self):
graph = Graph({
"a": set(["b", "d"]),
"b": set(["a"]),
"c": set([]),
"d": set([]),
"e": set([])
}, digraph=True)
self.assertTrue(graph.predecessors("a") == set(["b"]))
self.assertEqual(len(graph.predecessors("a")), 1)
def test_disconnect_without_vertices(self):
graph = Graph(digraph=True)
self.assertFalse(graph.sucessors("a") == set(["c"]))
self.assertFalse(graph.predecessors("a") == set(["c"]))
self.assertEqual(graph.in_degree("a"), 0)
self.assertEqual(graph.out_degree("a"), 0)
graph.disconnect("a", "c")
self.assertFalse(graph.sucessors("a") == set(["c"]))
self.assertFalse(graph.predecessors("a") == set(["c"]))
self.assertEqual(graph.in_degree("a"), 0)
self.assertEqual(graph.out_degree("a"), 0)
def test_disconnect_with_inexistent_vertex(self):
graph = Graph({
"a": set(["b", "d"]),
"b": set(["a"]),
"c": set([]),
"d": set([]),
"e": set([])
}, digraph=True)
graph.disconnect("a", "z")
graph.disconnect("a", "y")
graph.disconnect("a", "h")
self.assertFalse(graph.sucessors("a") == set([]))
self.assertFalse(graph.predecessors("a") == set([]))
self.assertNotEqual(graph.in_degree("a"), 0)
self.assertNotEqual(graph.out_degree("a"), 0)
self.assertTrue(graph.sucessors("a") == set(["b", "d"]))
self.assertTrue(graph.predecessors("a") == set(["b"]))
self.assertEqual(graph.in_degree("a"), 1)
self.assertEqual(graph.out_degree("a"), 2)
def test_connect(self):
graph = Graph({
"a": set(["b", "d"]),
"b": set(["a"]),
"c": set([]),
"d": set([]),
"e": set([])
}, digraph=True)
graph.connect("a", "c")
self.assertTrue(graph.predecessors("a") == set(["b"]))
self.assertTrue(graph.sucessors("a") == set(["b", "d", "c"]))
self.assertEqual(graph.in_degree("a"), 1)
self.assertEqual(graph.out_degree("a"), 3)
