#We add another countries in the loop
graph = Graph(g)
graph.add_edge(("Mumbai", "Delhi"),400)
graph.add_edge(("Delhi", "Kolkata"),500)
graph.add_edge(("Kolkata", "Bangalore"),600)
graph.add_edge(("TX", "NY"),1200)
graph.add_edge(("ALB", "NY"),800)

g = graph.adj_mat()

def bfs_connected_components(graph):
    connected_components = []
    nodes = graph.keys()

    while len(nodes)!=0:
        start_node = nodes.pop()
        queue = [start_node] #FIFO
        visited = [start_node]
        while len(queue)!=0:
            start = queue[0]
            queue.remove(start)
            neighbours = graph[start]
            for neighbour,_ in neighbours.iteritems():
                if neighbour not in visited:
                    queue.append(neighbour)
                    visited.append(neighbour)
                    nodes.remove(neighbour)
        connected_components.append(visited)

    return connected_components

print bfs_connected_components(g)