def test_add_vertex(self):
"""Tests the add_vertex method with an empty graph.
"""
graph = Graph()
self.assertFalse(graph.contains_vertex('A'), 'The graph does not contain A yet.')
graph.add_vertex('A')
self.assertTrue(graph.contains_vertex('A'), 'The graph now contains A.')
def test_add_vertex_existing_one(self):
"""Tests the add_vertex method in a graph where the vertex to add already exists.
"""
data = { 'A' : ['B'] }
graph = Graph(graph=data)
connected = graph.connected_vertex('A')
self.assertTrue(graph.contains_vertex('A'), 'Graph contains the vertex A.')
self.assertEqual(connected[0], 'B', 'A has an edge to vertex B.')
graph.add_vertex('A')
connected = graph.connected_vertex('A')
self.assertTrue(graph.contains_vertex('A'), 'Graph still contains vertex A.')
self.assertEqual(connected[0], 'B', 'A still has an edge to vertex B.')
def test_is_connected(self):
# Returns False for an empty graph
v, w = self.v, self.w
g = Graph([v, w], [])
eq_(g.is_connected(), False)
# Returns True for a complete graph
g.add_all_edges()
eq_(g.is_connected(), True)
# Returns False when a new vertex is added
x = Vertex('x')
g.add_vertex(x)
eq_(g.is_connected(), False)
# Returns True when edge is added to connect it
e2 = Edge(w, x)
g.add_edge(e2)
eq_(g.is_connected(), True)
def extract_connected_component(graph, needle):
subgraph = Graph([needle])
queue = [needle]
step = 0
while queue:
vertex = queue.pop(0)
step += 1
if step % 10000 == 0:
print(len(queue), repr(queue[0:min(5, len(queue))]))
step = 0
for (pred, obj) in graph.edges[vertex]:
# examine all neighbours of vertex
if not obj in subgraph.vertices:
# we haven't visited this vertex before
subgraph.add_vertex(obj)
subgraph.add_edge(vertex, obj, label=pred)
# we also needle to consider all new neighbours of `obj`
queue.append(obj)
elif (pred, obj) not in subgraph.edges[vertex]:
# we already have `obj`, but not this edge
subgraph.add_edge(vertex, obj, label=pred)
return subgraph
print("The maximum degree of the graph is:")
print(graph.Delta())
print("The minimum degree of the graph is:")
print(graph.delta())
print("Edges:")
print(graph.edges())
print("Degree Sequence: ")
ds = graph.degree_sequence()
print(ds)
fullfilling = [[2, 2, 2, 2, 1, 1], [3, 3, 3, 3, 3, 3], [3, 3, 2, 1, 1]]
non_fullfilling = [[4, 3, 2, 2, 2, 1, 1], [6, 6, 5, 4, 4, 2, 1], [3, 3, 3, 1]]
for sequence in fullfilling + non_fullfilling:
print(sequence, Graph.erdoes_gallai(sequence))
print("Add vertex 'z':")
graph.add_vertex("z")
print(graph)
print("Add edge ('x','y'): ")
graph.add_edge(('x', 'y'))
print(graph)
print("Add edge ('a','d'): ")
graph.add_edge(('a', 'd'))
print(graph)
from graphs import Graph
# Instantiate graphs (default not directed)
graph1 = Graph()
directed_graph1 = Graph(True)
# Instantiate vertices
vertex1 = Vertex("Value vertex 1")
vertex2 = Vertex("Value vertex 2")
vertex3 = Vertex("Value vertex 3")
vertex4 = Vertex("Value vertex 4")
vertex5 = Vertex("Value vertex 5")
vertex6 = Vertex("Value vertex 6")
# Adding vertex to graph1
graph1.add_vertex(vertex1)
graph1.add_vertex(vertex2)
graph1.add_vertex(vertex5)
graph1.add_vertex(vertex6)
# Adding vertex to directed_graph1
directed_graph1.add_vertex(vertex3)
directed_graph1.add_vertex(vertex4)
# Adding edges in graphs
graph1.add_edges(vertex1, vertex2, 5)
graph1.add_edges(vertex1, vertex5, 10)
graph1.add_edges(vertex1, vertex6, 15)
directed_graph1.add_edges(vertex3, vertex4)
print("\nVertices in non-directed Graph")
#!/usr/bin/python3
# Implement adjacency list
from graphs import Vertex, Graph
if __name__ == '__main__':
g = Graph()
for i in range(6):
g.add_vertex(i)
g.add_edge(0, 1, 5)
g.add_edge(0, 5, 2)
g.add_edge(1, 2, 4)
g.add_edge(2, 3, 9)
g.add_edge(3, 4, 7)
g.add_edge(3, 5, 3)
g.add_edge(4, 0, 1)
g.add_edge(5, 4, 8)
g.add_edge(5, 2, 1)
for v in g:
for w in v.get_connections():
print('({}, {})'.format(v.get_id(), w.get_id()))
