Networkx - Shortest path length

Question

I\'m using networkx to manage large network graph which consists of 50k nodes.

I want to calculate the shortest path length between a specific set of node

Answer 1

import networkx as nx
G=nx.Graph()
G.add_nodes_from([1,2,3,4])
G.add_edge(1,2)
G.add_edge(3,4)
try:
    n=nx.shortest_path_length(G,1,4)
    print n
except nx.NetworkXNoPath:
    print 'No path'

Answer 2

Alternatively, depending on the type of graph--namely, directed, strongly or weakly connected, or undirected--create component subgraphs (sub_G), that is,

(G.subgraph(c) for c in connected_components(G))

or if directed:

nx.weakly_connected_component_subgraphs(G) or nx.strongly_connected_component_subgraphs(G)

Furthermore, given sub_G is a directed graph, check for the strength of its connections, e.g.

nx.is_strongly_connected(sub_G) or ng.is_weakly_connected(sub_G)

Combined or individually, these recommendations'll reduce unnecessary checking of paths that do not exist due to the nature of the component subgraph(s).