def test_create_directed_graph(self):
"""Create a graph."""
graph = Graph(is_directed=True)
graph.add_vertex('A')
graph.add_vertex('B')
graph.add_vertex('C')
graph.add_edge('A', 'B')
graph.add_edge('A', 'C')
graph.add_edge('B', 'C')
self.assertEqual(len(graph.get_vertices()), 3)
self.assertEqual(len(graph.get_neighbors('A')), 2)
self.assertEqual(len(graph.get_neighbors('B')), 1)
self.assertEqual(len(graph.get_neighbors('C')), 0)
def test_neighbors():
g = Graph()
vertex_apple = g.add('apple')
vertex_banana = g.add('banana')
vertex_cake = g.add('cake')
vertex_dog = g.add('dog')
vertex_egg = g.add('egg')
vertex_foo = g.add('foo')
g.add_edge(vertex_apple, vertex_banana)
g.add_edge(vertex_cake, vertex_dog, 2)
g.add_edge(vertex_dog, vertex_egg, 4)
expected_apple = g.get_neighbors(vertex_apple)
expected_dog = g.get_neighbors(vertex_dog)
expected_foo = g.get_neighbors(vertex_foo)
assert expected_apple == [('banana', 1)]
assert expected_dog == [('cake', 2), ('egg', 4)]
assert expected_foo == []
def test_get_neighbors():
graph = Graph()
banana = graph.add_node('banana')
apple = graph.add_node('apple')
graph.add_edge(apple, banana, 44)
neighbors = graph.get_neighbors(apple)
assert len(neighbors) == 1
neighbor_edge = neighbors[0]
assert neighbor_edge.vertex.value == 'banana'
assert neighbor_edge.weight == 44
