def test_add_edge(self):
o, p = object(), object()
g = c.DiGraph((o, p))
self.assertEqual(g.size, 0)
self.assertFalse(g.has_edge(o, p))
self.assertFalse(g.has_edge(p, o))
g.add_edge(o, p)
self.assertTrue(g.has_edge(o, p))
self.assertFalse(g.has_edge(p, o))
self.assertEqual(g.size, 1)
e = g.edges
self.assertIn((o, p), e)
self.assertNotIn((p, o), e)
self.assertIn(p, g[o])
self.assertNotIn(o, g[p])
g.add_edge(p, o)
self.assertTrue(g.has_edge(o, p))
self.assertTrue(g.has_edge(p, o))
self.assertEqual(g.size, 2)
e = g.edges
self.assertIn((o, p), e)
self.assertIn((p, o), e)
self.assertIn(p, g[o])
self.assertIn(o, g[p])
def test_degree(self):
e = {(0, 1), (1, 2), (2, 3), (3, 4), (1, 4)}
g = c.DiGraph(range(6), e)
for i, v in enumerate((1, 3, 2, 2, 2, 0)):
self.assertEqual(g.degree(i), g.in_degree(i) + g.out_degree(i))
self.assertEqual(g.degree(i), v)
def test_neighbors(self):
e = {(0, 1), (1, 2), (2, 3), (3, 4), (1, 4)}
g = c.DiGraph(range(6), e)
self.assertEqual(g.neighbors([1]), {1: {2, 4}})
self.assertEqual(g.neighbors([1])[1], g[1])
self.assertEqual(g.neighbors([2, 4]), {2: {3}, 4: set()})
def test_adjacency_map(self):
v, e = set(range(1, 4)), {(1, 3), (1, 4), (2, 4), (3, 2)}
g = c.DiGraph(v, e)
m = g.adjacency_map
self.assertEqual(m, {1: {3, 4}, 2: {4}, 3: {2}, 4: set()})
m[1].add(2)
self.assertFalse(g.has_edge(1, 2), "Adjacency map mutated the graph.")
def test_add_edges_nonexisting_vertices(self):
e = {(0, 1), (1, 2), (2, 3), (3, 4), (4, 1)}
g = c.DiGraph(edges=e)
self.assertEqual(g.vertices, set(range(5)))
for u, v in e:
self.assertTrue(g.has_edge(u, v))
self.assertFalse(g.has_edge(v, u))
def test_add_edges(self):
e = {(0, 1), (1, 2), (2, 3), (3, 4), (1, 4)}
g = c.DiGraph(range(6), e)
for u, v in e:
self.assertTrue(g.has_edge(u, v))
self.assertFalse(g.has_edge(v, u))
e = {(3, 1), (5, 3), (5, 4), (4, 2)}
g.add_edges(e)
for u, v in e:
self.assertTrue(g.has_edge(u, v))
self.assertFalse(g.has_edge(v, u))
def test_edges(self):
e = {(1, 5), (2, 5), (5, 2), (5, 1), (3, 4)}
g = c.DiGraph(range(1, 6), e)
self.assertEqual(g.edges, e)
def test_add_path(self):
g = c.DiGraph(range(6), {(1, 4)})
e = {(0, 1), (1, 2), (2, 3), (3, 4), (4, 5), (1, 4)}
g.add_path(range(6))
self.assertEqual(g.edges, e)
def test_add_edge_cant_add_loop(self):
g = c.DiGraph({1})
self.assertRaises(exc.EdgeCreatesLoop, g.add_edge, 1, 1)
def test_is_simple(self):
g = c.DiGraph()
self.assertFalse(g.is_directed)
self.assertFalse(g.is_multigraph)