def test_remove_node_ESize(self):
"""
verify that the node has been removed and all the edges he was connected with
also verify the ESize
this test will be preformed over a simple graph looks like:
1◄--►3
| ▲
| /
▼ ▼
2
"""
g = DiGraph() # create a new graph
g.add_node(1) # add two nodes to g
g.add_node(2)
g.add_node(3)
g.add_edge(1, 2, 12)
g.add_edge(1, 3, 13)
g.add_edge(2, 3, 23)
g.add_edge(3, 2, 32)
g.add_edge(3, 1, 31)
self.assertEqual(5, g.ESize)
g.remove_node(3)
self.assertEqual(1, g.ESize)
self.assertEqual(
12,
g.get_edge(1, 2).weight
) # verify that the only edge remaining is 1-->2 in weight of 12
self.assertEqual(None, g.get_edge(2, 1))
self.assertTrue(g.has_edge(1, 2))
self.assertFalse(g.has_edge(2, 1))
self.assertFalse(g.has_edge(3, 1))
self.assertFalse(g.has_edge(1, 3))
def test_get_edge(self):
g = DiGraph()
g.add_node(1)
g.add_node(2)
g.add_node(3)
g.add_node(4)
g.add_edge(1, 2, 3.3)
g.add_edge(2, 2, 4.4)
self.assertEqual(g.get_edge(2, 2), 4.4)
def test_add_edge(self):
"""
This test verify that connect (node1,node2) is not equal to connect (node2,node1),
also that negative weight and connect nodes that are not in the graph is not allow
"""
g = DiGraph() # create a new graph
g.add_node(1) # add two nodes to g
g.add_node(2)
g.add_node(3)
self.assertFalse(g.add_edge(1, 6, 1)) # node6 is not in the graph
self.assertFalse(g.add_edge(
1, 1, 5)) # cannot add edge between node to himself
self.assertTrue(g.add_edge(1, 2, 12)) # add edge between (1,2)
self.assertFalse(g.add_edge(
1, 2, 12)) # there is edge already between (1,2) with this weight
self.assertFalse(g.add_edge(
1, 2,
1)) # does not allow update in place there is an edge already
self.assertTrue(g.add_edge(2, 1,
12)) # allows to add edge between (2,1)
self.assertEqual(g.get_edge(2, 1).weight, 12)
self.assertFalse(g.add_edge(2, 1, 6))
self.assertFalse(g.add_edge(1, 3,
-4)) # should not allow negative weight
