def set_cost(self, vertex1, vertex2, cost) :
if vertex1 not in self.__neighbours or vertex2 not in self.__neighbours :
raise exceptionGraph("The vertices are invalid")
if vertex2 not in self.__neighbours[vertex1] :
raise exceptionGraph("The edge doesn't exist")
if (vertex1, vertex2) in self.__dictionaryCosts.keys() :
self.__dictionaryCosts[(vertex1, vertex2)] = cost
else :
self.__dictionaryCosts[(vertex2, vertex1)] = cost
def add_edge(self, vertex1, vertex2, cost) :
if vertex1 not in self.__neighbours.keys() or vertex2 not in self.__neighbours.keys() :
raise exceptionGraph("Vertices do not exist")
if self.is_edge(vertex1, vertex2) :
raise exceptionGraph("The edge already exists")
if vertex1 == vertex2 :
raise exceptionGraph("There can't be an edge from a vertex to itself")
self.__neighbours[vertex2].append(vertex1)
self.__neighbours[vertex1].append(vertex2)
self.__dictionaryCosts[(vertex1, vertex2)] = cost
def remove_edge(self, vertex1, vertex2) :
if vertex1 not in self.__neighbours.keys() or vertex2 not in self.__neighbours.keys() :
raise exceptionGraph("Vertices do not exist")
if not self.is_edge(vertex1, vertex2) :
raise exceptionGraph("The edge doesn't exist")
self.__neighbours[vertex2].remove(vertex1)
self.__neighbours[vertex1].remove(vertex2)
if (vertex1, vertex2) in self.__dictionaryCosts.keys() :
self.__dictionaryCosts.pop((vertex1, vertex2))
else :
self.__dictionaryCosts.pop((vertex2, vertex1))
def read_file(file):
try:
f = open(file, 'r')
except exceptionGraph:
raise exceptionGraph("The file is not available")
firstLine = f.readline().strip().split()
graph = Graph(0)
number_of_vertices = int(firstLine[0])
line = f.readline()
while line != "":
edge = line.strip().split()
vertex1 = int(edge[0])
vertex2 = int(edge[1])
if vertex1 not in graph.parse_vertices():
graph.add_vertex(vertex1)
if vertex2 not in graph.parse_vertices() and vertex2 != -1:
graph.add_vertex(vertex2)
if len(edge) == 3 and vertex1 != vertex2 and not graph.is_edge(
vertex1, vertex2):
graph.add_edge(vertex1, vertex2, int(edge[2]))
line = f.readline()
if number_of_vertices != graph.get_nr_of_vertices():
for vertex in range(number_of_vertices):
if vertex not in graph.parse_vertices():
graph.add_vertex(vertex)
f.close()
return graph
def validate_edge(edge):
try:
edge = edge.strip().split(",")
vertex1 = int(edge[0])
vertex2 = int(edge[1])
return vertex1, vertex2
except exceptionGraph:
raise exceptionGraph("The input is invalid\n")
def remove_vertex(self, vertex) :
if vertex not in self.__neighbours.keys() :
raise exceptionGraph("Vertex doesn't exist")
self.__vertices -= 1
for neighbours in self.__neighbours[vertex] :
self.__neighbours[neighbours].remove(vertex)
if (neighbours, vertex) in self.__dictionaryCosts.keys() :
self.__dictionaryCosts.pop((neighbours, vertex))
else :
self.__dictionaryCosts.pop((vertex, neighbours))
self.__neighbours.pop(vertex)
def random_graph(number_of_vertices, number_of_edges):
minimum = input("Minimum cost: ")
minimum = validate_vertex(minimum)
maximum = input("Maximum cost: ")
maximum = validate_vertex(maximum)
if number_of_edges > number_of_vertices * number_of_vertices:
raise exceptionGraph("The nr of edges must be < than nrVertices^2")
graph = Graph(number_of_vertices)
for vertex in range(number_of_edges):
cost = random.randint(minimum, maximum)
vertex1 = random.randrange(0, number_of_vertices)
vertex2 = random.randrange(0, number_of_vertices)
while graph.is_edge(vertex1, vertex2) or vertex1 == vertex2:
vertex1 = random.randrange(0, number_of_vertices)
vertex2 = random.randrange(0, number_of_vertices)
graph.add_edge(vertex1, vertex2, cost)
return graph
def validate_vertex(vertex):
try:
vertex = int(vertex)
return vertex
except ValueError:
raise exceptionGraph("Please add an integer\n")
def parse_neighbours(self, vertex) :
if vertex not in self.__neighbours.keys() :
raise exceptionGraph("Vertex does not exist")
return self.__neighbours[vertex]
def get_vertex_degree(self, vertex) :
if vertex not in self.__neighbours.keys() :
raise exceptionGraph("Vertex does not exist")
return len(self.__neighbours[vertex])
def is_edge(self, vertex1, vertex2) :
if vertex1 not in self.__neighbours.keys() or vertex2 not in self.__neighbours.keys() :
raise exceptionGraph("Vertices are not valid")
return vertex2 in self.__neighbours[vertex1]
def add_vertex(self, vertex) :
if vertex in self.__neighbours.keys() :
raise exceptionGraph("Vertex already exists")
self.__neighbours[vertex] = []
self.__vertices += 1
